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Holley just announced that they are releasing the standard CAN protocol.
Andrew
Great news. That is an open door for DIYers. Now you don't need the second CANBUS port. LMK if you need any custom stuff interfaced to it. I've designed a rapid development platform for myself that can do CANBUS, Bluetooth, relay drivers, PWMs, temp sensors, input pots, displays, 0 to 5 volt analog out, etc.
Great news. That is an open door for DIYers. Now you don't need the second CANBUS port. LMK if you need any custom stuff interfaced to it. I've designed a rapid development platform for myself that can do CANBUS, Bluetooth, relay drivers, PWMs, temp sensors, input pots, displays, 0 to 5 volt analog out, etc.
Do you by chance have a library made for interpretation of the data? I see that there are some utilities that will take the dbc and make it into a struct but haven't had a chance to dig into it since I just started to get back into this project.
No, I haven't dug into this yet. I don't have a holley system to test it with anyway.
Yes, there are tools that can work with DBC to convert them to excel for example. I've created tools to generate "C" code from excel before for my touch screen, but I don't have any plans for the native holley data unless a need comes up.
No, I haven't dug into this yet. I don't have a holley system to test it with anyway.
Yes, there are tools that can work with DBC to convert them to excel for example. I've created tools to generate "C" code from excel before for my touch screen, but I don't have any plans for the native holley data unless a need comes up.
Ok, hopefully I can get something going this winter and I'll be sure to link it here. Maybe it'll help someone down the line.
It's just a 2" SPI TFT panel in a housing I milled out of acetal hooked up to an esp32 dev board. I've already got a few modules planned out and they will talk to each other using the native TWAI (CAN) interface on the esp32. The whole thing has sprung from using a .92" OLED and Arduino nano to display speed and activate lockup over 45mph with a vss and MR to Hall effect converter, to basically designing and implementing a whole modern style architecture.
It's just a 2" SPI TFT panel in a housing I milled out of acetal hooked up to an esp32 dev board. I've already got a few modules planned out and they will talk to each other using the native TWAI (CAN) interface on the esp32. The whole thing has sprung from using a .92" OLED and Arduino nano to display speed and activate lockup over 45mph with a vss and MR to Hall effect converter, to basically designing and implementing a whole modern style architecture.
That's how it starts. I pull canbus data from an AEM infinity for the touchscreen in my vette.
It not only does the lockup, but controls the entire 4L80E and everything else in the car.
LSswap thank you so much for pulling this information together and sharing with the community! I have an Arduino Nano Every with 2 MCP2515 modules set up and I'm running into a small problem. I have 1 MCP2515 that is reading the Current Gear from Holley using the Racepak protocol as you have shown above. That is working excellent. Now I am trying to use the 2nd MCP215 to output the gear to a Powertrain Control Solutions gear indicator. The gear indicator states that it will accept GMLAN or J1939 protocols. I have attempted communication on both protocols based on information in the links below but I am getting error code 6 from the sendMsgBuf subroutine.
#include <Arduino.h>
#include <mcp_can.h>
#include <SPI.h>
MCP_CAN sendCAN(10); // Set CS to pin 10
void setup() {
// put your setup code here, to run once:
pinMode(readCAN_INT, INPUT);
Serial.begin(115200);
// Initialize MCP2515 running at 8MHz with a baudrate of 250kb/s and the masks and filters disabled.
if (sendCAN.begin(MCP_ANY, CAN_250KBPS, MCP_8MHZ) == CAN_OK)
Serial.println("MCP2515 Initialized Successfully on Pin 10!");
else
Serial.println("Error Initializing MCP2515...on Pin 10");
sendCAN.setMode(MCP_NORMAL); // Change to normal mode to allow messages to be transmitted
}
byte dataToScreen[8] = { 0xFB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
void loop() {
// put your main code here, to run repeatedly:
sendCAN();
}
void sendCAN(){
byte sndStat = sendCAN.sendMsgBuf(0x18F00504, 1,8, dataToScreen);
if(sndStat == CAN_OK){
Serial.println(dataToScreen[0]);
Serial.println("Message Sent Successfully!");
} else {
Serial.println("Error Sending Message...");
Serial.println(sndStat);
}
delay(100); // send data per 100ms
}
Any input would be extremely appreciated!
Last edited by cjohnson6772; Jan 21, 2025 at 10:26 AM.
First thing I see is that you've got two different things named "sendCAN" One is a subroutine and the other is an instance of the CAN library. I don't think it's the cause of your problem but... change the subroutine name for less confusion.
You problem is that there is nothing on the receiving end of the canbus wires. Hook something up that expects the same speed and protocol and it should go away. I tested this with my current J1939 CANBUS encoder project.
What does that gear indicator cost anyway? Their we site seems to be hacked or someting.
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Does that display already have canbus in it? 
