how many do you need ? you can have up to 8 of these devices
if you need more there are other port expanders that are on different
addresses
On 4/6/2018 11:31 AM, Neil Hancock wrote:
> yassyass, This seems to be 6yr old question ~ I got the Bone script JS
> working using cloud9 IDE for an MCP23017 last year -
> I got it working on 4.4.54-ti-r93 and I think I had problems
> with the later build 4.4.68-ti-r108
>
> I was beginner to BBB, but I had used I2C a lot in uP C env. I choose
> BBB to implement a project reading from a number of MCP23017 - and
> then it was used by JS networking that somebody else did
>
> I found the documentation to be clear that it does work, and the code
> traceable... but it did take some digging, and as ever prototyping the
> interface, characterizing the interface and building on top of it. I
> used an adafruit prototype cape to prove I could interface to the I2C.
>
> However I also found late into the project, that I could only init one
> I2C at a time...... I wonder if anybody else found a way to have two
> I2C operational at the same time.??
>
> My issue was that I wanted to add a number of MCP23017 - more MCP23017
> than one I2C bus could support.
>
>
> It was contract work for me, so here are some snippets,
>
> enable-pins.sh:
> sudo config-pin overlay cape-universaln
> config-pin p9.17 i2c
> config-pin p9.18 i2c
> echo try: cat /sys/devices/platform/bone_capemgr/slots
>
> BbbMcp23017.js:
> var b = require('bonescript');
> var kelly_i2c = require('i2c'); //npm install i2c
> https://github.com/kelly/node-i2c
>
>
> //From
> https://stackoverflow.com/questions/7545641/javascript-multidimensional-array
> Array.matrix = function(numrows, numcols, initial) {
> var arr = [];
> for (var i = 0; i < numrows; ++i) {
> var columns = [];
> for (var j = 0; j < numcols; ++j) {
> columns[j] = initial;
> }
> arr[i] = columns;
> }
> return arr;
> }
> var mcp_act1 = Array.matrix(2,8,false);
> var locMcp0 = new kelly_i2c(mcp0_addr+0, {device : i2cloc_port});
> //var remMcp0 = new kelly_i2c(mcp0_addr+0, {device : i2crem_port});
> doesn't seem to support init two different busses
>
> //the mcp23017 B&Aregs are read into the following 16 bit array.
> b15-8(Binputs) b7-0(Ainputs)
> //Init value represents OFF for all 16 stations
> var mcpRead = Array.matrix(2,8,0); // [I2c#][mcp16bitIndex] 16bit
> station values
>
> //******************************************************************************
>
>
> if (zero) {
> locMcp0.writeBytes(0x04,[0xff,0x03], function(err){ if (err)
> {mcp0_act[0]=false;console.log('writeBytes1 err'+err);} } );
> if (typeof remMcp0 == 'object') {
> remMcp0.writeBytes(0x0C,[0xff,0xff], function(err){ if (err)
> {mcp0_act[1]=false;console.log('writeBytes2 err'+err);} } );
> } else {
> mcp1_act[0]=false;
> }
>
> //Write INTCON 1 to each GPINTCON/0x08 GPINTENB to enable
> interrupt monitoring - DEFVAL is 0, so ints on GPIO PIN=1
> locMcp0.writeBytes(0x08,[0xff,0xff], function(err){ if (err)
> {mcp0_act[0]=false;console.log('writeBytes1 err'+err);} } );
> if (typeof remMcp0 == 'object') {
> remMcp0.writeBytes(0x0C,[0xff,0xff], function(err){ if (err)
> {mcp0_act[1]=false;console.log('writeBytes2 err'+err);} } );
> } else {
> mcp1_act[0]=false;
> }
> }
>
> if (1==mcpInputPullup) {
> //Write 0xFF to each GPPUA/0x0C GPPUB/0x0D to enable pullup 100K,
> Bank=0
> locMcp0.writeBytes(0x0C,[0xff,0xff], function(err){ if (err)
> {mcp0_act[0]=false;console.log('writeBytes1 err'+err);} } );
> if (typeof remMcp0 == 'object') {
> remMcp0.writeBytes(0x0C,[0xff,0xff], function(err){ if (err)
> {mcp0_act[1]=false;console.log('writeBytes2 err'+err);} } );
> } else {
> mcp1_act[0]=false;
> }
> }
>
> mcp_poll('init'); //First time through, then on timer
>
> function doMeter1(x) {
> if(x.err) {
> console.log('do1:x.err = ' + x.err);
> return;
> }
> timer_poll = setInterval(sweep1, poll_mcp_sec*993);
> }
>
> function sweep1() {
> mcp_poll(''); //only on this sweep
> }
>
> function mcp_poll(msg_dbg)
> {
> //var date = new Date();
> //var timeNow = dateFormat(date,'HH:MM:ss.l');
> var mcpNmLoc=0;
> poll_count++;
> //console.log(timeNow+' ['+poll_count+']'+msg_dbg +'
> mcp0='+mcp0_act[0]+' mcp1=' +mcp1_act[0]);
>
> if (true == mcp1_act[mcpNmLoc]) {
> // console.log('mcp1_act['+mcpNmLoc+'] poll');
> //Set mcp addr to GPIOA 0x12 or INTFA 0x0E
> remMcp0.writeByte(0x12,function (err) { if (err) {
> console.log('mcp1wr:'+err.message); } });
> remMcp0.read(2, function(err,rdData) {
> if (err) {
> console.log('mcp1rd:'+err);
> mcp1_act[mcpNmLoc]=false;
> } else {
> onReadMcp1(mcpNmLoc,rdData);
> }
> });
> }
>
> mcpNmLoc=0;
> /* Called last so that it runs update_pwm_all() */
> if (true == mcp0_act[mcpNmLoc]) {
> //console.log( 'mcp0_act['+mcpNmLoc+'] poll');
> //Set mcp addr to GPIOA 0x12 or INTFA 0x0E
> locMcp0.writeByte(0x12,function (err) { if (err) {
> console.log('mcp0wr:'+err.message); } });
> locMcp0.read(2, function(err,rdData) {
> if (err) {
> console.log('mcp0rd:'+err);
> mcp0_act[mcpNmLoc]=false;
> } else {
> onReadMcp0(mcpNmLoc,rdData); //This does work of recording data
> ////act on it
> }
> });
> } else {
> console.log("mcp0_act false, error no flow Output generated");
> }
> }
>
> function onReadMcp0(mcpNmRd,rdValue) {
> mcpRead[0][mcpNmRd] =rdValue[0] | (rdValue[1]<<8);
> //console.log('mcpRead[0]['+mcpNmRd+ ']='
> +mcpRead[0][mcpNmRd].toString(hex) );
> }
>
>
>
> On Wed, Apr 4, 2018 at 3:34 PM, yassyass <[email protected]
> <mailto:[email protected]>> wrote:
>
> I would like to ask the same question that klemenz is asking. Does
> cloud9 provide a framework to run i2c slaves with js or python?
>
> On Wednesday, March 7, 2012 at 10:44:32 PM UTC+13,
> [email protected] <mailto:[email protected]> wrote:
>
> Hi Dan,
>
> Is there an i2c support within cloud9ide environment or more
> precisely within bonescript custom .js?
>
> thanks
>
> Dne sobota, 31. december 2011 22:07:43 UTC+1 je oseba Dan
> napisala:
>
> Stan,
> Thanks for the info. I was able to get i2cdetect to work
> with a 3.3V
> device, and will give the level shifter a shot (when I
> have one) for
> the 5V device.
> Poking around further, I'm guessing the
> /sys/class/i2c-adapter
> approach mentioned in my question #4 works only if there
> is a kernel
> module for the device. For example, there is a
> kernel-module-bmp085
> for the BMP085 barometric sensor.
> For everything else, there is the i2cget and i2cset
> approach that you
> recommended.
> Thanks,
> Dan.
> On Dec 30, 9:55 pm, Stan Seibert <[email protected]> wrote:
> > On Dec 30, 4:50 pm, Dan <[email protected]> wrote:
> >
> > > 1. Should the pullup resistors always be connected to
> 3.3V (as opposed
> > > to some other voltage) on the Beaglebone? I used 5K
> resistors - is
> > > that close enough? (the SRM says 5.5K).
> >
> > 5k resistors should be fine (I used 4.7k with my
> device), and since
> > the I/O voltage on the board is 3.3V, you should only
> connect the pull-
> > ups to that. (Pin 3 or 4 on P9)
> >
> > > 2. Are pins 19 and 20 connected to i2c2 or i2c3? The
> SRM manual says
> > > i2c2, but based on the results of i2cdetect and other
> posts I think
> > > it's i2c3. Is there an i2c2 on the Beaglebone?
> >
> > The numbering in the OS seems to be different than the
> numbering in
> > the SRM. Pins 19 and 20 are on i2c2 in the hardware
> numbering scheme,
> > but in Linux, the device name is /dev/i2c-3.
> >
> > > 3. Should i2cdetect automatically find thei2cdevice at
> the correct
> > > address if everything is hooked up correctly?
> >
> > That depends on your device and whether it will respond
> to the read
> > probes that i2cdetect uses, but in general, yes.
> >
> > > 4. Do I always need to enter a command similar to the
> one in Koen's
> > > article: "echo bmp085 0x77 >
> /sys/class/i2c-adapter/i2c-3/
> > > new_device"? Is the "bmp085" part just a label that I
> choose, or does
> > > it need to precisely match some setting in the device?
> >
> > I just interact with my device using the i2cget and
> i2cset command
> > line tools, following the data sheet for my device to
> know what data
> > addresses on the device to set and get.
> >
> > > 5.Is a 5V device like theBlinkMsupported by the
> BeagleboneI2C? If
> > > so, is the process for configuring it any different
> from the process
> > > described in Koen's blog post? (This is the device I
> tried to get
> > > working, and I'm guessing it's not supported).
> >
> > I've never tried using a 3.3V master and a 5VI2Cdevice,
> but I have
> > used this level shifter for the other direction with an
> Arduino (5V
> > master and 3.3V device):
> >
> > http://www.sparkfun.com/products/8745
> <http://www.sparkfun.com/products/8745>
> >
> > (The description and comments were kind of confusing for
> this board.
> > I used the TX on channel 1 and 2 for theI2CSDA and SCL.)
>
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