Arduino Software Serial Even Parity Example
Feb 22, 2016 - If a small packet (very small!) is 20 bytes, and there is corruption 0.5% of those packets, this indicates a 0.5% / 20 bytes per packet / 8 bits per byte (assuming 7 data bits, 1 parity bit, for example). Vray For Sketchup 2014 Free Download Full Version. This comes out to 0.003% errors. Note that parity checks only work for 1-bit errors - in fact, a 2-bit error (in the.
I'm using an external serial device with 9600 baud and even parity. Using Arduino's HardwareSerial I was able to call Serial.begin(9600, SERIAL_8E1). But I need to run this device on AltSoftwareSerial. I already changed (New)SoftwareSerial to receive the parity bit but AltSoftSerial's code is much more advanced. Actually: fortunately it is more advanced I plan on adding Parity support in three small steps: • receive the parity bit without evaluating it • calculate parity on received byte and compare it • transfer with parity When I will have managed to implement step 3 I also should have obtained enough knowledge about AltSoftSerial to implement different stop bit lengths as well as different data bit lengths.
I'm new to using hardware timers in more than the most basic ways and right now I'm researching on how the comparator works, Google 'ICR1 328' yields a lot of results. I guess I have to read the parity bit in the 'ISR(CAPTURE_INTERRUPT)' function.
Yes, I wrote AltSoftSerial. As far as I know, nobody has ever successfully modified AltSoftSerial's format, or managed to hack on the code in any meaningful way. Hopefully you'll be the first. If you have an oscilloscope, those commented out lines inside ISR(CAPTURE_INTERRUPT) can help you to 'see' when the code is executing, relative to the incoming waveform. Jqgrid Export To Excel Demo Javascript Download.
There's 2 useful pairs commented out. If you have a 4 channel scope, you could set each to different pins. But even a cheap 2 channel scope using 1 channel for the incoming serial waveform and the other channel for only one pair at a time will really help. The Descent Part 2 Ita Download Free. As you work on the code, you can place those lines within your parity capture and easily see on the scope screen if you've got it at the correct place. If you don't have a scope, there are a number of cheap microcontroller-based logic analyzers and scope projects, some can even run on Arduino hardware (of course, I hope you're using a Teensy.) They have limited performance, but if you set the baud rate to something slow like 1200, those tools should work fine. You might need to add a delayMicroseconds() in the code before driving the pin low so the pulse is wide enough to be seen. You can always test at slow speeds to get the software logic right, then delete or comment that stuff out when you're done.
The reception uses a simple state machine, where 'state' is the index of the bit number. Bit 0 is the start bit, 1 to 9 are the data bits, and 10 is the stop bit. So look for this part. Paul, I'm happy to finally deliver a patch that enables the use of AltSoftSerial.begin(baud, config) in the same way Arduino's HardwareSerial does. I was able to verify it using a Leonardo as logic analyzer at 1200 baud and my actual setup at 9600 baud with even parity.
I also checked odd parity but I did not yet try all the other combinations (5 data bits, 2 stop bits.). Actually getting the logic analyzer running was the hardest part. I only have one Leonardo and a couple of 3V Arduino Minis, all my other devices are Teensy 3.0 and I needed an ATmega328 like board, but that's off topic. Working with your code was a great adventure! I tried my best to adapt your coding style, please correct me as much as you can. I was aware of hardware timers and even guessed their part in PWM output almost correctly, but the advanced features you make use of did not come to my attention. The RAM usage grows by 6 bytes to store configuration and state data, and the CPU overhead increases by a couple of conditions and additions.
I believe my modifications don't cause enough additional overhead to degrade AltSoftSerial's performance at high baud rates. I will continue my development on this patch and post results as soon as I feel comfortable enough with OLS & my SUMP compatible. Hello Paul, I was wondering if this AltSoftSerial still active. I to give it a try on a SparkFun Pro Micro. What I need to do or like is to emulate a 2560 as close as possible in a smaller package. I have to talk to a serial port @ 9600 8N2 and one at 57600.