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// Bus Frequency Row 12
int Pval = (DCSParams[12][5] << 24) | (DCSParams[12][4] << 16) | (DCSParams[12][3] << 8) | DCSParams[12][2];
float PvalFloat = static_cast<float>(Pval) / 1000.0;
Serial.print("Row 12 Bus Frequency: ");
Serial.print(PvalFloat);
Serial.println(" Hz");
delay(5);// Bus Frequency Row 12
int Pval = 0;
for (int i = 5; i >= 2; --i) {
Pval = (Pval << 8) | DCSParams[12][i];
}
float PvalFloat = static_cast<float>(Pval) / 1000.0;
Serial.print("Row 12 Bus Frequency: ");
Serial.print(PvalFloat);
Serial.println(" Hz");
delay(5);
Oh yes for sure I wasn't meaning your code specifically just to future readers really...your code was just handy to use as an example, for the others reading this and the sir/madam that asked about the math it is basically just this (again using kloppk's code as an example hahaI agree the code can be more concise. It was the first pass at decoding the data to get it to work. I was simply evolving the code to get it to work. I was going for "function over form" initially. Now that it's working it could certainly be made more concise.
Back when I started doing some programming in my career we had to use IBM punch cards. Editing involved shuffling the cards and dropping them into the optical card reader again and again.
Once done the deck was marked with a marker making a diagonal stripe on the side of the deck just in case you dropped the deck. That gave one a fighting chance to get the deck back in the right order. The program decks were stored in long cardboard boxes.
uint8_t DCSParams[] = {
0x93, 0x02, 0xCC, 0x07, 0x5A
};
uint8_t calcChecksum(const uint8_t* data) {
uint8_t checksum = data[0];
const uint8_t data_size = data[1] + 3;
for (std::size_t index = 1; index < data_size - 1; ++index)
checksum ^= data[index];
return checksum;
}
uint32_t decodeResponse(const uint8_t* data) {
uint32_t result = 0;
const uint8_t response_size = data[1] + 3;
const uint8_t current_checksum = data[response_size - 1];
const uint8_t expected_checksum = calcChecksum(data);
if (expected_checksum == current_checksum) {
for (int i = response_size - 1; i >= response_size - data[1]; --i) {
result = (result << 8) | data[i - 1];
}
return result;
}
printf("Invalid checksum, expected 0x%.2X got 0x%.2X\n", expected_checksum, current_checksum);
return result;
}
void printData(const char* name, const char* units, const uint8_t* data, const float factor = 1.0f) {
printf("%s %.2f%s\n", name, static_cast<float>(decodeResponse(data)) / factor, units);
}
int main() {
printData("Battery Voltage:", "V", DCSParams, 100.0f);
return 0;
}DCSParams = [0x93, 0x02, 0xCC, 0x07, 0x5A]
def calc_checksum(data):
checksum = data[0]
data_size = data[1] + 3
for index in range(1, data_size - 1):
checksum ^= data[index]
return checksum
def decode_response(data):
result = 0
response_size = data[1] + 3
current_checksum = data[response_size - 1]
expected_checksum = calc_checksum(data)
if expected_checksum == current_checksum:
for i in range(response_size - 1, response_size - data[1] - 1, -1):
result = (result << 8) | data[i - 1]
return result
print(f"Invalid checksum, expected 0x{expected_checksum:02X} got 0x{current_checksum:02X}")
return result
def print_data(name, units, data, factor=1.0):
decoded_value = decode_response(data)
print(f"{name} {decoded_value / factor:.2f}{units}")
if __name__ == "__main__":
print_data("Battery Voltage:", "V", DCSParams, 100.0)
You mean the kids up and coming today couldn't just summon Siri to aid in that?I agree the code can be more concise. It was the first pass at decoding the data to get it to work. I was simply evolving the code to get it to work. I was going for "function over form" initially. Now that it's working it could certainly be made more concise.
Back when I started doing some programming in my career we had to use IBM punch cards. Editing involved shuffling the cards and dropping them into the optical card reader again and again.
Once done the deck was marked with a marker making a diagonal stripe on the side of the deck just in case you dropped the deck. That gave one a fighting chance to get the deck back in the right order. The program decks were stored in long cardboard boxes.
