September 21st, 2010 by Trevor Coult
A while ago I wrote an article for beginners on programming the Tekin RS using the HotWire interface and software. That was based on HotWire 4/Vegas 2/firmware 203. Now that Vegas 208/HotWire 5 has been released it is time to update the article as the interface has changed considerably. For those who want it though the original article is available here.
The majority of 12th scale drivers in the UK now run LiPo batteries and 10.5 turn brushless motors, so the article will be based on these. Most of the function descriptions apply to other classes and motors though.
Whether you are performing a new installation or upgrading, do not plug the HotWire interface into the PC yet, wait until you have installed the software. The drivers are installed along with the software and these have to be present before connecting the HotWire.
Most of the things described here are not in the Tekin RS user manual. It is still essential to read this though as it has loads of valuable information, such as calibrating the RS to your transmitter, error codes and troubleshooting etc.
I am putting this near the beginning as this is one of the things people will be looking for! There are several situations that give people problems when first upgrading to 208 and they are all easy to solve.
If the RS lights come on when it is switched on, but there is no chime or other response, it is because the RS is not getting the voltage it is expecting. The usual reason for this is that the voltage cutoff has been set too high e.g. set to 2S when using a 1S LiPo. Go into the HotWire software and change this to the correct value. The other main reason is that the booster or Rx pack isn’t connected or turned on.
Always recalibrate the RS to your transmitter after a software upgrade. If the RS won’t calibrate (refuses to chime at a point in the calibration) check the following things. Try the calibration again with the throttle reversed. Several makes of transmitter require this including KO and Futaba. Make sure your endpoints are set to their default values. If they are set too low (e.g. brakes practically turned off) the RS will not recognise the endpoint and will not calibrate.
If the timing tab in the HotWire software is blank after upgrading the software it is because one of the preset timing profiles has been set. Change to one of the custom profiles and all the sliders will appear.
Down to Business
The RS comes with firmware version 180 installed, so the first thing most people will want to do is to get the latest version. This can be found at http://www.teamtekin.com/hotwire.html. You first have to register. After registration you are emailed instructions on how to download the software. If you try to do this and it takes you back to the registration screen again, chances are you don’t have cookies enabled in your web browser, so enable them and go through the process again. You will end up with a file called TekinHotWire.exe on your computer. This file needs to be run to install or upgrade the HotWire software.
If you are upgrading the install process will uninstall the old version first, then install the new one. During the install you will be asked which user interface you want to have installed as shown in the dialog below.
The full version is the version with the extra graphics around the main display area and enhanced visuals within it. The express version has a rectangular window and simplified internal graphics. I have installed the full version on my main laptop and the express version on my netbook.
Now you can plug in your HotWire interface for the first time. Windows will go through it’s device detection process and the device will be installed. After this has completed unplug the HotWire from the PC again. The reason for this is because you have to connect the HotWire to the RS before connecting it to the PC, it will not work otherwise.
Time to do this now. Plug the HotWire into the RS, then the HotWire into the PC. Then run the HotWire software. For a while you will get the following screen while the software finds the HotWire.
If the software cannot find the HotWire the following message will be shown.
There are several possible reasons for this but the usual ones are either not making sure the USB cable is plugged fully into the HotWire, or plugging things together in the wrong order as described above. If you have a green light on the HotWire, and a single red light on the RS it has been connected correctly. If any of these lights are missing or all the red lights are lit on the RS it hasn’t.
If the RS has a version of the firmware installed that is earlier than 208 you will get the following message.
This is because the new software is not compatible with firmware versions earlier than 208, so click on the OK button and follow the upgrade instructions shown on the screen. Remember not to unplug anything until the upgrade process is complete.
When the HotWire is discovered and the speed controller has been upgraded if necessary, the default RS setup screen will be shown as below.
This is the full version. If you have installed the express version it will look like this.
The red/black rectangles are buttons. The button on the bottom right is the Advanced button. Clicking this will open the interface out and show further options as below.
The first section we are interested in is the one that lets us upgrade the firmware on the RS. This is shown in more detail here.
The Current Version area shows the current firmware on the RS. As the RS has to be upgraded in order to run the software this will say 208, as will the list of firmware version below it. When future versions are released they will appear in the list and it will be possible to select which version to install. The process of upgrading is simple. First select the firmware version to be upgraded to from the list. A new button will now appear below the list labelled Update ESC. Click this button and follow the instructions given. That’s it! Just one thing to remember, don’t unplug anything until the entire process is completed. If you do this you have the possibility of ending up with an RS that will need to go back to Tekin to be reset. You have been warned!
After upgrading exit the HotWire software and unplug everything. It is important to then recalibrate the RS to your transmitter as this will have been reset during the upgrade process. Then reconnect everything and run the software again.
Now for a description of the various sections and sliders use to program the RS. On the full interface all of the sliders look like the one on the left. Above and below each slider is a button which can be used for fine adjustment of each slider. Directly above the slider it’s current value is shown. The slider pointer itself can be dragged up and down by the mouse. You can also click on the sliders themselves above or below the pointer which will change the values by different increments depending on the range of the slider.
If you hover the mouse over the title of the slider a hint will be shown giving a more detailed description of the function of the slider. This sometimes also gives hints on how the function should be used.
If you right click on the slider you get a menu where it is possible to select from a range of preset values for the function.
On the express interface the sliders look like the one shown here. They work in exactly the same way as described above though.
The HotWire software interface has now been split into several different pages or tabs. These are dashboard, setup, brake, throttle and timing as can be seen below.
The dashboard tab shows all the current settings for the timing profile currently selected on the RS. If dual mode is selected it will look like the one below, showing the timing advance settings.
If sensored mode is selected it will look like the one below, showing both the timing boost settings and the turbo settings.
In both cases the text at the bottom will give the majority of the settings for the currently selected profile.
Voltage Cutoff – When running LiPo batteries it is advisable to set a voltage cutoff to prevent accidentally over discharging of the cells. If this happens they are permanently damaged. Preset values are available for different LiPos or a custom cutoff voltage level can be set. The lowest value of the slider used to turn the cutoff off, but now it sets a cutoff for 1S LiPos. If this is set too high for the voltage of the cells being used the RS will not operate.
Motor Type – This sets both the type of motor used, brushed or brushless, and also whether the speed control is runs with brakes only or with reverse. For 12th scale stock and most other current classes this should be set to brushless forward only, BL-FW.
Timing Profile – This is the major new area introduced with the latest HotWire version. There are 5 fixed timing profiles and two customisable profiles. These can be set directly on the RS by following the instructions in the manual for setting the throttle profile. Setting the throttle profile is no longer possible directly from the RS but is still available in the HotWire software.
The profile settings are as follows:
TP1 – No boost and the RS LED flashes. This is the no timing stock spec setting with the flashing LED so the setting can be verified by scrutineering.
TP2 – 15 degrees of boost, 5442 to 20000 RPM rev range.
TP2 – 25 degrees of boost, 5442 to 20000 RPM rev range.
TP2 – 35 degrees of boost, 5442 to 20000 RPM rev range.
TP2 – 45 degrees of boost, 5442 to 20000 RPM rev range.
C1 – User customisable.
C2 – User customisable.
When one of the fixed profile settings are selected (TP1-TP5) it is not possible to change any of the timing values and the timing tab will be blank.
Reverse Motor – This changes the normal rotation of the motor to clockwise. Not much use on a 12th scale unless you custom build a car with the motor the other way round to normal!
1S LiPo – When this is not checked, the voltage cutoff slider is used to set a cutoff voltage. The RS assumes it will be powered via the main battery and checks this for the correct voltage to power the RS. When this is checked, the RS assumes it will be powered via the RX lead and will check this for correct voltage to power the ESC.
Sensored and Dual Mode check boxes – Only one of these can be set at a time. When Sensored is checked the speed control runs in sensored mode, using the sensor wire and the hall sensors in the motor to detect the position of the rotor. This enables all the advanced timing functions of the RS so is the usual setting for stock classes. Dual Mode runs the motor in sensored mode when the throttle is initially opened, but then switches to sensorless. This is more often used in the modified classes as it is more efficient than sensorless only.
Drag Brake – This controls the amount of brake that is applied when the throttle is a neutral. In 12th scale this is often set to 0, though with some stock motors there is little rolling resistance and in these cases a value between 5 and 10 can be useful. Drag Brake and Push Control are normally mutually exclusive; if you use one set the other to 0.
Brake Strength – This controls the level of braking that is available. In 12th scale the brakes are rarely used except to stop the car at the end of the race. Just in case I have to use them though I usually set the value just below 100 in order to smooth the out a little but still be able to stop the car quickly in the event of an emergency.
Push Control – This gives a small amount of throttle for a short time when the trigger or stick has been returned to neutral. It is similar to trimming your transmitter to have a small amount of throttle, but as it turns off after a short time it has the advantage of not having to hold the car on the brakes at the start. Remember that Drag Brake and Push Control are mutually exclusive.
Throttle Profile – This is the same as setting a throttle curve on your transmitter. Setting 3 is a linear response. Higher numbers give a positive curve, lower ones a negative curve.
Neutral Width – This is the amount the throttle stick or trigger is moved before the RS thinks it is not at the neutral position any more. This is a case of personal preference, though it is not advisable to set a value below 5 or the RS may not be able to register the neutral value correctly. Transmitter neutral values can drift and there needs to be some margin to allow this.
Current Limit – This limits the amount of current that is sent to the motor. It can be useful to tame the power of a modified motor.
Reverse Speed – This controls the maximum speed of reverse. In 12th scale this would not be used as reverse is not permitted.
It is now possible to set RPM values when the RS is set to Dual Mode. If this is the case the timing tab will show the Timing Advance slider and the RPM setting section. This controls the RPS at which the timing advance is introduced, and when it will reach it’s maximum value.
Operation of this is similar to it’s use in sensored mode. If sensored is set the timing tab shows Timing Advance, Boost and Turbo sections.
Timing Advance – This sets the amount of added timing to the motor. It is not measured in degrees but as a percentage. 100 means 100 percent, but is somewhere between 25 and 30 degrees of added timing. It is useful to set this to 100 even when running sensored only as if the sensor cable is damaged the speed control will switch to sensorless mode and run the motor with this timing advance setting.
Boost – This is the amount of extra timing added to the motor. This is shown in degrees. The way this timing is introduced to the motor depends on the RPM settings.
The End RPM has to be set first. Once this value has been set the button underneath, labelled Calc RPMs has to be clicked. This will calculate all the possible Start RPMs for the End RPM that has been set and show them in the Start RPM list. One of these values then has to be selected.
An example. The values shown here are a start RPM of 2757 and an end RPM of 10502. If timing boost has been set to 40 degrees, the timing set by this will not start to come in until the motor has reached 2757 RPM, and will have the full 40 degrees of timing when the motor reaches 10502 RPM.
Turbo – This is another method of adding timing to the motor, and is also shown in degrees. This is introduced after a certain amount of time at full throttle.
Turbo Delay – The amount of time you have to be at full throttle before the Turbo starts to come in. The speed it comes in is set by the Turbo Ramp setting described later.
Turbo Ramp defines the speed at which Turbo comes in. There are three possible values, 1.0 being the slowest and 3.0 being the quickest. Overall, Turbo will not come in until you have been on full throttle for the amount of time set by the Turbo Delay setting, and the will come in at the speed defined by the Turbo Ramp setting until it reaches the timing value set by the Turbo slider. This is most useful on tracks with a long main straight where the car is reaching maximum speed early. Turbo can be used to effectively give the car a “second gear”. On typical 12th scale tracks with an up to 30m straight I have rarely found Turbo to be necessary if the Boost settings have been made correctly, but can give that extra little bit if there is a sweeper onto/off the straight.
Below are the starting point settings I recommend for someone first using an RS with a 10.5 motor in 12th scale using a 1S LiPo. These should be regarded as a baseline and are conservative. Additional tuning should be performed according to the motor used, driving style and track size and layout in order to get the best out of the RS. The motor settings shown are for a Tekin Redline 10.5.
Motor Timing: 0 degrees
Rollout: 58mm per rev (subtract about 10mm per rev for NiMh)
Drag Brake: 5
Reverse Strength: Off
Brake Strength: 96
Neutral Width: 10
Motor Type: BL-FW
Throttle Profile: 3
Voltage Cutoff: 1S
Push Control: Off
Reverse Motor: Off
1S LiPo: On
Turbo Delay: n/a
End RPM: 10516
Start RPM: 2758
Turbo Ramp: n/a
For the latest setups visit the Tekin Team Driver Setups page at http://www.teamtekin.com/hotwire/ESCsetups/index.html.
For people who want to know more about the Tekin RS and it’s settings in detail Mark Brown has written a very detailed article which is available at http://rcfaq.weebly.com/tekin-rs–hotwire.html. This for 203 but the vast majority still applies now.
Thanks to Tekin team manager Randy Pike for help and advice while writing this article.
This entry was posted on Tuesday, September 21st, 2010 at 11:37 am and is filed under Reviews, Technical articles. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.