Sorry for the delay getting back guys, my mum had a nasty fall yesterday and broke her hip. I was posting here when I got the call.
She is comfortable in hospital and it's my sisters turn to visit so I have a bit of free time.
Here is the ESP32 code I used
These are the connections to the ESP32
This is the Usersetup.h file with the changes from default. This needs to go in the TFT_eSPI library
So the TFT_eSPI is the only library you need for this to work.
If anyone wants to start from basics this is first successful attempt at reading the IVT shunt for an Arduino Uno R4 WiFi using a transciever on pins 10 and 13. It will display the voltage and current in the serial console
Code: Select all
// IVT-S meter using Arduino Uno R4 WiFi built-in CAN controller
// Reads both Current and Voltage from IVT-S sensor
#include <Arduino_CAN.h>
// IVT-S CAN message IDs (check your documentation to confirm)
static const uint32_t IVT_CURRENT_ID = 0x521; // Current message ID
static const uint32_t IVT_VOLTAGE_ID = 0x522; // Voltage message ID (common alternative: 0x522)
// Variables to store readings
int32_t current_ma = 0;
int32_t voltage_mv = 0;
unsigned long lastUpdate = 0;
void setup() {
Serial.begin(115200);
while (!Serial) delay(10);
Serial.println("Initializing CAN at 500kbps...");
if (!CAN.begin(CanBitRate::BR_500k)) {
Serial.println("Failed to initialize built-in CAN controller!");
while (1) delay(1000);
}
Serial.println("Built-in CAN controller initialized at 500kbps");
Serial.println("Waiting for IVT-S Current and Voltage data...");
Serial.println("---------------------------------------------");
}
void loop() {
if (CAN.available()) {
CanMsg const msg = CAN.read();
if (msg.id == IVT_CURRENT_ID && msg.data_length >= 6) {
// Parse current value (bytes 2-5 as little-endian signed int32)
current_ma = (int32_t)(
msg.data[2] |
(msg.data[3] << 8) |
(msg.data[4] << 16) |
(msg.data[5] << 24)
);
lastUpdate = millis();
}
else if (msg.id == IVT_VOLTAGE_ID && msg.data_length >= 6) {
// Parse voltage value (bytes 2-5 as little-endian signed int32)
// Voltage is typically in millivolts (mV)
voltage_mv = (int32_t)(
msg.data[2] |
(msg.data[3] << 8) |
(msg.data[4] << 16) |
(msg.data[5] << 24)
);
lastUpdate = millis();
// Display both current and voltage when voltage is updated
displayReadings();
}
}
// Display readings every second even if no new data
if (millis() - lastUpdate >= 1000) {
displayReadings();
lastUpdate = millis();
}
delay(10);
}
void displayReadings() {
// Convert to more readable units
float current_a = current_ma / 1000.0; // mA to A
float voltage_v = voltage_mv / 1000.0; // mV to V
Serial.print("Current: ");
Serial.print(current_a, 3); // 3 decimal places
Serial.print(" A (");
Serial.print(current_ma);
Serial.print(" mA) | Voltage: ");
Serial.print(voltage_v, 1); // 1 decimal place
Serial.print(" V (");
Serial.print(voltage_mv);
Serial.println(" mV)");
}
As mentioned earlier I am hopeless at writing code so all of this was written by Deep Seek.
