ModMyPi MCP23017 pHAT

MrBroccoli · February 11, 2020, 2:09am

My finger is ready to pull the ‘buy’ trigger on one of these, but I thought I had better check here first… Are these compatible with Zynthian to run the rotary encoders, and if they are, any idea on what settings I might use?

smiths73v3 · February 12, 2020, 12:41am

The single should work.
Should be self-explanatory if you can follow the zynthain All-In-One schematic. The trick will be either running GND from different pins on J1 for each encoder GND, or chaining them together.
zynthian_allinone.sch.svg
If you want to use arduino style encoder boards, you’ll also need to run a +V to each encoder as well.

MrBroccoli · February 12, 2020, 2:09am

ok, i think i get all that nearly… maybe i just can’t yet see where that gnd connects to… i would have hoped not from the gpio, because of the tft hat that has to go on as well.

As luck would have it, that lead me to this :-

which has visible breakouts for GND too… and it is cheaper.

Thanks, @smiths73v3 I will get there!

wolfpaw98 · February 12, 2020, 2:10am

If you’re not in a rush and want to spend a little less, you could try one of these: https://www.aliexpress.com/item/32880817899.html?spm=a2g0o.productlist.0.0.315f2528pfled6&algo_pvid=53582668-c6f3-4abc-a13b-4d245b1fd3c5&algo_expid=53582668-c6f3-4abc-a13b-4d245b1fd3c5-18&btsid=1430e0e3-1a4c-48ad-bba4-cd1b40d3844d&ws_ab_test=searchweb0_0,searchweb201602_6,searchweb201603_53

MrBroccoli · February 12, 2020, 2:15am

yeah, they were the other option i looked at but i think i like the hats better

smiths73v3 · February 23, 2020, 7:38pm

@MrBroccoli, might take much longer than you want to wait but I’m working on my own solution.

MrBroccoli · April 14, 2020, 10:58am

How do I find the right values to configure this with zynthian?

i2cdetect -y 1

Shows me 0x20 and 0x21 are available

i2cdump -y 1 0x20

Shows the some parameters that change if I turn dials.

How do I decode these values to the correct ones for zynthian?

Thanks

wyleu · April 14, 2020, 1:29pm

I’ve not tried that…
I’ll have a play.

MrBroccoli · April 14, 2020, 8:21pm

This is what I see when i run :-

i2cdump -y 1 0x20

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: ff ff 00 00 ff ff 00 00 00 00 22 22 ff ff 00 00    ..........""....
10: ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00    ................
20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................

le51 · April 15, 2020, 6:29am

Hi,
I do not really understand where the problem is, it looks like everything IS working as it should.

le51 · April 15, 2020, 8:29am

github.com

zynthian/zyncoder/blob/55d4f31e4b8a819603bf528fa1f2972cc0a57ae6/zyncoder.c#L128


		zynswitches[i].enabled=0;
		zynswitches[i].midi_event.type=NONE_EVENT;
	}
	for (i=0;i<MAX_NUM_ZYNCODERS;i++) {
		zyncoders[i].enabled=0;
		for (j=0;j<ZYNCODER_TICKS_PER_RETENT;j++) zyncoders[i].dtus[j]=0;
	}
	wiringPiSetup();


#ifdef MCP23017_ENCODERS
	init_mcp23017(MCP23017_BASE_PIN, 0x20, MCP23017_INTA_PIN, MCP23017_INTB_PIN, zyncoder_mcp23017_bank_ISRs);
#else
	mcp23008Setup (MCP23008_BASE_PIN, 0x20);
	init_poll_zynswitches();
#endif
	return 1;
}


int end_zyncoder() {
	return 1;
}

i2c address is hardcoded in zyncoder library

MrBroccoli · April 15, 2020, 10:30am

The problem is that my dials still do nothing on the zynthian screen. On the hardware menu of the webgui, I need to chose the right hardware type, and then pick which pins should be configured, but I’m not sure what the values should be. I included the i2c stuff to show my dials are on the bus but I’m stuck now.

le51 · April 15, 2020, 11:45am

Ok, I see. It depends on how you have wired encoders to mcp23017.

kit V3-pro correspond to this schematic: https://github.com/zynthian/zynthian-hw/blob/master/ZynScreen/OzzMaker/ZynScreen%20_v1.3.pdf
kit V3 to that one :https://github.com/zynthian/zynthian-hw/blob/master/zynthian_allinone/zynthian_allinone.sch.svg

they differ only regarding INTA and INTB wiring

and maybe it helps:

wyleu · April 15, 2020, 2:52pm

The coluorful table on this thread Encoder mapping for Direct I/O connection give details of what should go in the weconf setup … it’s the values from the WPi column…

MrBroccoli · April 15, 2020, 3:22pm

I am not using either of these kits. I am using the “IO Plus” from the third entry on this post, which has mcp23017’s connected via i2c

MrBroccoli · April 15, 2020, 3:24pm

Isn’t this table used when you directly connect the dials to gpio? I am not doing that. I am using MCP23017’s via i2c.

wyleu · April 15, 2020, 3:27pm

Well there is that, but I am VERY proud of having got the table together, so humour me a bit . . .

https://discourse.zynthian.org/uploads/default/original/2X/4/43c3171a7e2b4b0dba535a20e0b2203d5e8a7498.svg

The encoder pin mappings is there . . .

MrBroccoli · April 15, 2020, 3:32pm

K, sure. Your colouring skills on this table are incredible, not only because they highlight the correct pin use for direct GPIO connections, but also they provide the perfect derailment for my issue. I couldn’t have done it without you.

As for the diagram… I followed this wiring diagram original to wire up, but it doesn’t explain to me what values I need to add to the web conf page.

le51 · April 15, 2020, 3:40pm

Depending on the diagram you have used (see my post above), and strictly follow of course, you juste have to chose the right kit, the pins wiring page will be updated accordingly.

MrBroccoli · April 15, 2020, 3:44pm

When you say “have to chose the right kit”, does that mean I have to use zynthian hardware kit?