As part of the Arduino class I'm teaching at the Art Center College of Design in Pasadena, CA, US, I want to demonstrate some techniques you can use to check the validity of Serial data. I'm like to set up one Arduino board to auto-generate some ASCII data...some of it correct, some of it garbled...and be able to have that one board stream it to numerous student Arduino boards in the class.
Can I just do something as simple as just split the signal coming out of the master Arduino's TX pin and have each student plug a lead into their board's RX pin? With no connection back to the master board? It seems doubtful to me.
If that won't work, any suggestions on how I could accomplish this?
If you also connected the ground pins of the boards together it should work. The more boards you add, however, the more likely you will have communication errors due to increased loading on the pin (keeping the wires short will help).
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The Gadget Shield: accelerometer, RGB LED, IR transmit/receive, speaker, microphone, light sensor, potentiometer, pushbuttons
Hi, if you want to show your circuit prowess as well, and show that the real world sometimes needs buffering, you could use the Everyman's Chip: the 555.
This is billed as a Timer, and it is often used for that, but it has a nice 200ma output rating, driving both high and low. You can use 5V power (not the 12V on the diagram) and have a nice strong signal to send around the Lab, and protect your Arduino from short circuits etc. Just this simple:
BTW you can also use 12V or higher power and have your Arduino drive it, so it's also a Power Buffer. Sometimes it's used to drive high power FETs which switch 10's of amps.
Any electronics lab or guys you know should have a few 555s, even Radio Shack.
DISCLAIMER: Mentioning stuff from my own shop... which contains all the stuff I think is cool...
...Or you can buy 8 of them for $10 from me. Which sounds ridiculous Except they are part of a big assortment for the 10 bucks, which includes 71 other popular chips.
I also make up kits for schools and Universities and Maker groups...
Hope your class has fun... The fact that you are considering error checking (Not taken seriously enough by most Arduino coders) is a good sign you're serious.