marce002
100 W
is a Bitwise XOR? what library should be included?
Last edited:
VOTOL serial communication protocol
- Thread starter flute2k3@hotmail.com
- Start date
Michael9dk
10 mW
@marce002
Yes it's a bitwise XOR, that is part of the C language, so it is already included.
Update:
I fixed the code parts that were changed by forum formatting.
Yes it's a bitwise XOR, that is part of the C language, so it is already included.
Update:
I fixed the code parts that were changed by forum formatting.
C++:
/*
* Original code from trufinv. See:
* https://www.endless-sphere.com/sphere/threads/using-fardrivers-lin-protocol.120345/#post-1805274
* https://www.endless-sphere.com/sphere/threads/votol-serial-communication-protocol.112970/page-2#post-1805276
*/
const unsigned int SIF_PIN = 2;
short battery = 0;
short current = 0;
short currentPercent = 0;
short rpm = 0;
long faultCode = 0;
bool regen = false;
bool brake = false;
unsigned long lastTime;
unsigned long lastDuration = 0;
byte lastCrc = 0;
byte data[12];
int bitIndex = -1;
void setup()
{
Serial.begin(115200);
Serial.println("Begin.");
pinMode(SIF_PIN, INPUT);
lastTime = micros();
attachInterrupt(digitalPinToInterrupt(SIF_PIN), sifChange, CHANGE);
}
void loop()
{
// put your main code here, to run repeatedly:
}
void sifChange()
{
int val = digitalRead(SIF_PIN);
unsigned long duration = micros() - lastTime;
lastTime = micros();
if (val == LOW)
{
if (lastDuration > 0)
{
bool bitComplete = false;
float ratio = float(lastDuration) / float(duration);
if (round(lastDuration / duration) >= 31)
{
bitIndex = 0;
}
else if (ratio > 1.5)
{
// bit value 0
bitClear(data[bitIndex / 8], 7 - (bitIndex % 8));
bitComplete = true;
}
else if (1 / ratio > 1.5)
{
// bit value 0
bitSet(data[bitIndex / 8], 7 - (bitIndex % 8));
bitComplete = true;
}
else
{
Serial.println(String(duration) + "-" + String(lastDuration));
}
if (bitComplete)
{
bitIndex++;
if (bitIndex == 96)
{
bitIndex = 0;
byte crc = 0;
for (int i = 0; i < 11; i++)
{
crc ^= data[i];
}
if (crc != data[11])
{
Serial.println("CRC FAILURE: " + String(crc) + "-" + String(data[11]));
}
if (crc == data[11] && crc != lastCrc)
{
lastCrc = crc;
for (int i = 0; i < 12; i++)
{
Serial.print(data[i], HEX);
Serial.print(" ");
}
Serial.println();
battery = data[9];
battery = data[9];
current = data[6];
currentPercent = data[10];
rpm = ((data[7] << 8) + data[8]); // * 1.91; TODO: Change ratio to match wheel-size/motor gearing.
brake = bitRead(data[4], 5);
regen = bitRead(data[4], 3);
Serial.print("Battery %: " + String(battery));
Serial.print(" Current %: " + String(currentPercent));
Serial.print(" Current A: " + String(current));
Serial.print(" RPM: " + String(rpm));
if (brake) Serial.print(" BRAKE");
if (regen) Serial.print(" REGEN");
Serial.println();
}
}
}
}
}
lastDuration = duration;
}
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marce002
100 W
Thanks Michael9dk i will try and report back
Michael9dk
10 mW
I have tested it on Votol EM-70 and get rpm, current (A), regen, etc.
Notice current switches between charge/discharge at 128.
Notice current switches between charge/discharge at 128.
marce002
100 W
It compiled ok, but i cant see anything in my serial monitor,,, i have connected the line to my RX on nano... with a simple serial input i can read something so i know it is reading, but with your code nothing shows up, what can i have wrong?
this is my serial with a sinle code using 9600
if(Serial.available()){
c = Serial.read();
Serial.println(c,HEX);
FFFFFFFF
30
FFFFFF8C
FFFFFF8E
FFFFFF8C
FFFFFFCC
FFFFFF8E
FFFFFF8C
FFFFFFCC
...
this is my serial with a sinle code using 9600
if(Serial.available()){
c = Serial.read();
Serial.println(c,HEX);
FFFFFFFF
30
FFFFFF8C
FFFFFF8E
FFFFFF8C
FFFFFFCC
FFFFFF8E
FFFFFF8C
FFFFFFCC
...
Michael9dk
10 mW
Try increasing baud rate to 115200. 9600 is too slow for the implemented timings.
marce002
100 W
but the votol controller is talking at 9600 right? should i change with pc soft app? i have changed just in code and still nothing.. I have connected the single line wire , to my ARDUINO NANO pin labelled RX , is this ok right?
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Michael9dk
10 mW
Edit: it's actually 667 Hz.
---, but trufinv's code uses timing, to detect high/low bits.
Did you set SIF_PIN to the input you use.
Did you see "Begin" on your serial output.
---, but trufinv's code uses timing, to detect high/low bits.
Did you set SIF_PIN to the input you use.
Did you see "Begin" on your serial output.
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marce002
100 W
I use pin labelled RX so i left the code a pin 2 right? yes i can see Begin but nothing else.. thks
Guys, this is not serial communication. Just use any port that supports hardware interrupts. The actual bits are being determined by the algorithm. If you're getting bad results when the controller is in PWM mode (wheel moving) keep in mind that these controllers give huge EMI. Shielding, shorter cables, proper solders, etc fixes these issues.
Look at the protocol documentation that I posted here to get a better understanding of how this works.
Also keep in mind that ESP32 and arduino handle data types and hardware interrupts a bit differently. I remember having to do some slight changes when moving to ESP32. Try to limit the interrupt function just for getting the data and do the processing in the loop elsewhere.
Look at the protocol documentation that I posted here to get a better understanding of how this works.
Also keep in mind that ESP32 and arduino handle data types and hardware interrupts a bit differently. I remember having to do some slight changes when moving to ESP32. Try to limit the interrupt function just for getting the data and do the processing in the loop elsewhere.
Michael9dk
10 mW
Oh yes, the EMI is through the roof here. Kind of hard to collect reliable data for a Odometer.
had issues displaying the data on an external display also. Fixed by using usb cable with shielding for data transfer. Also instead of checking like this: "if (ratio > 1.5)", you could just compare the values like lastDuration > duration. It seems to provide more accurate data. Also avoid any kind of float operations in the interrupt if you're using ESP32.
Michael9dk
10 mW
Thanks for the tips, trufinv.
Im using a Raspberry Pi Pico (with Arduino-pico in Arduino IDE).
Im using a Raspberry Pi Pico (with Arduino-pico in Arduino IDE).
marce002
100 W
attached is my teraterm log, it seems to be receiving data, can anyone tell me if its the same data you would expect?
LOGGED SESION IS: turned on, accelerated and brake then turned off.
LOGGED SESION IS: turned on, accelerated and brake then turned off.
Michael9dk
10 mW
I'm not familiar with Teraterm, so can't read the log-output as it is.
Remember trufinv's implementation is not using the regular serial-reader. It might be possible to implement with a serial UART input, but I haven't had success with my (few) experiments. A software-defined serial implementation is probably the best way to do it.
I see some possibilities to improve trufinv's excellent proof-of-concept.
- sync on >900 Tosc Low, followed by 32 Tosc High.
- filter EMI where period is below 32 Tosc.
- filter EMI where period is above 64 Tosc.
@trufinv With 32us <Tosc <320us, Can you clarify wether Tosc is a constant time of 1/9600 (104 microseconds) or 32*Tosc ?
marce002
100 W
i do not think is that complex... i do not know what is 32*Tosc and the like..... the log is pretty strightforward a lot or FFFFFFF BUT nothing useful....
Maybe some port on votol page to redirect signal to my wires? because my log is not having any data i can parse.....
Maybe some port on votol page to redirect signal to my wires? because my log is not having any data i can parse.....
YusufRizaldy
1 µW
Hello all, I tried implementing the code provided by @trufinv. I'm using an arduino nano with interrupt pin set at digital pin 2 (d2). got a very wonky reading on the Serial Monitor, found some CRC failure and the data frame bytes are mostly all zeroes. In most cases my nano are unable to determine whether the bit are 1 or 0. I think this happens the ratio parameters never seems to get beyond 1.5. I dont understand why this happens since i think the code are already correct. I post some of my serial monitor reading below:
20:21:26.783 -> No bit sampled.
20:21:27.000 -> 8 61 A 80 2 0 0 0 0 0 0 E1
20:21:27.000 -> Battery %: 0 Current %: 0 Current A: 0 RPM: 0
20:21:27.874 -> No bit sampled.
20:21:27.874 -> No bit sampled.
20:21:27.927 -> No bit sampled.
20:21:28.042 -> CRC FAILURE: 240-112
20:21:28.042 -> No bit sampled.
20:21:28.042 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.111 -> No bit sampled.
20:21:28.111 -> No bit sampled.
20:21:28.225 -> CRC FAILURE: 124-28
Thank you!
20:21:26.783 -> No bit sampled.
20:21:27.000 -> 8 61 A 80 2 0 0 0 0 0 0 E1
20:21:27.000 -> Battery %: 0 Current %: 0 Current A: 0 RPM: 0
20:21:27.874 -> No bit sampled.
20:21:27.874 -> No bit sampled.
20:21:27.927 -> No bit sampled.
20:21:28.042 -> CRC FAILURE: 240-112
20:21:28.042 -> No bit sampled.
20:21:28.042 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.076 -> No bit sampled.
20:21:28.111 -> No bit sampled.
20:21:28.111 -> No bit sampled.
20:21:28.225 -> CRC FAILURE: 124-28
Thank you!
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Can you share what your current setup is? I'd love to try this on my FarDriver and have a nicer external display. Thanks!
Well I have 3 of them, one ebike and 2 electric motorcycles. The displays are 0.96" SSD1306, 2" ST7789V and 3.2" ILI9341. The 0.96" is in a simple voltmeter/ignition enclosure and I use the KT display buttons to scroll between screens, for the other 2 I've designed and 3d printed enclossures (they also have a button on the side to scroll between screens). All are driven with esp32s
Attachments
Michael9dk
10 mW
Finally received my new oscilloscope and did some measurements.
992Tosc = 60 ms.
64Tosc = 1 ms.
32Tosc = 0.5 ms.
Restricting bits to fit these timings, might improve accuracy in a noisy environment.
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marce002
100 W
hello #TRUFINV
I'm trying to display Battery Volt like your picture in the OLED 0.96 display, but i find only 0 in that byte.... RPM, brake, and current seems to be working fine, but cant find any data for battery (despite that Volt is not present in the datasheet you were given) that is why I ask you how did you determine Volts in your OLDE picture post #69
my controller is 96v EM100 , OCT 2024 , maybe they changed something?
I'm trying to display Battery Volt like your picture in the OLED 0.96 display, but i find only 0 in that byte.... RPM, brake, and current seems to be working fine, but cant find any data for battery (despite that Volt is not present in the datasheet you were given) that is why I ask you how did you determine Volts in your OLDE picture post #69
my controller is 96v EM100 , OCT 2024 , maybe they changed something?
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i actually have it dual mode. most of the time I get my data (voltage included) via serial. when i connect my phone or laptop to the esp32 via bloetooth serial then I use the sif (display output) and forward the serial packages from the phone/pc to the votol so it can be programmed
marce002
100 W
Wow thks for you fast response!, But having a votol em100 and a proper connection to one line wire, my stm32 device is not showing up any data related to BATTERY V or BAT %, like if the datasheet would be wrong or outdated , retrieves always as 0 no data for battery, even less for VOLTS.... all the rest is fine like REGEN, brake, RPM and so on.... do you know what can it be? i mean nothing here:
battery = data[9];
battery = data[9];
fardrivers allow you to customize the sif packets up to a point whereas votols don't. however for me the votol is better as I can use the serial protocol that is well documented and works great and provides better data than the very limited sif packages.