Reputation from RROMANO001

RROMANO001 got a reaction from agaelema in I2C scanner for 2553 & 5529 July 24, 2016

Actual out of box experience:
I am new to Energia so I am still in the learning curve knee but about wire these are some FAQ or FIXUP:

First attempt was not working, using an LCD bought from ebay wiring was not same as library example so take care when you use these devices, I wrote a pin pulser to be able to identify how pin where connected using a multimeter or one LED with series resistor. (sketch attached as file on PCF 8574[A])

Wire is present on folder CORE, is required on folder WIRE to be attached as library, I placed for now a symbolic_link to original files and it cure both compile and library add too. Some library probably where developed on winzz so it suffer capitalization too on Linux and I suppose also on OSX, again link solved this problem before ask to cure problem.

during test for learning how library work I wrote a scanner very similar to one found on this thread to see what return as error, no timeout is on library, transaction get not locking but deadloking in case of unresponsive bus.
When P1.6 is Low Wire Library forever return 0 as if transaction was ok if no write and lock if no ack come back from device. This require more debugging inspection than just reading code.
Wire.endTransmission(stop) default to true as from source overloading, using () version forever generate <I2C stop>.

On launchpad P1.6 is attached green LED, this disturb I2C transaction and system forever hang or return OK, Logic analyser was reading ok but I suppose internal threshold is more higher than 1.8 volt and 1.9 where not enough. Seen observing LED glow and also attaching scope to measure bus parameter.
Removing LED P1.6 Jumper scanner and other sketch I tested worked fine.

LCD I bought on Ebay was not connected as from Library but I found was RS RW EN BL D4 D5 D6 D7, pulser can be useful to check how is connected, from china you get cheap items but at expense of our time.

More to come when I better know forum and Energia.
/* I2C Bit Pulse exerciser to identify pinout This sketch repeatedly pulse at 4 Second period every bit 5 time showing on serial console. example added 16 May 2015 by Roberto Romano modified by This example code is in the public domain. */ #include <Wire.h> #define I2CADDR 0x27 void setup() { // put your setup code here, to run once: Serial.begin(9600); // start serial for output Serial.println("I2C Pulser Begin"); Wire.begin(); // join i2c bus (address optional for master) } int errnum; void loop() { // put your main code here, to run repeatedly: Serial.println(); Wire.beginTransmission(I2CADDR); // Set and test Slave device Wire.write(0); errnum=Wire.endTransmission(); delay(5); Serial.print(" Errnum: "); Serial.print(errnum); if(errnum) else if(errnum) Serial.println(" -> I2C error!!!"); else { // Wire OK Serial.println(" -> OK"); for(int i=0;i<7;i++) { // bit scanner for loop Serial.print(" pulse on BIT: "); Serial.println(i); for(int j=0;j<5;j++) { // pulser loop Serial.print(" pulse High "); Serial.println(i); Wire.beginTransmission(I2CADDR); // Set and test Slave device Wire.write(1<<i); errnum=Wire.endTransmission(); delay(2000); Serial.print(" pulse Low "); Serial.println(i); Wire.beginTransmission(I2CADDR); // Set and test Slave device Wire.write(0); errnum=Wire.endTransmission(); delay(2000); } // pulser loop } // bit scanner for loop } // Wire OK }

RROMANO001 reacted to yyrkoon in TI will no longer accept .edu addresses for samples November 22, 2015

Is it just me, or are people getting a bit carried away with the term "Arduino" ?

RROMANO001 reacted to eck in TI will no longer accept .edu addresses for samples November 22, 2015

Most low end Cortex M0 and M3 chips aren't really that much more expensive if bought from e.g. Mouser vs from AliExpress. What comes to the boards, they can be usually recreated very easily if needed.

RROMANO001 reacted to cde in TI will no longer accept .edu addresses for samples November 22, 2015

Is teaching students to use unreliably sourced products wise and/or ethical? Won't that work against them in the field when they attempt to design based on unrealistic dev and production costs? Just a thought.

RROMANO001 reacted to solipso in TI will no longer accept .edu addresses for samples November 22, 2015

This is the exact board we choose as our learning platform. It's a small world!