12-Key Capacitive Touch Sensor Breakout - MPR121

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Guapa5000
 
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12-Key Capacitive Touch Sensor Breakout - MPR121

Post by Guapa5000 »

Yesterday I got my new 12-Key Capacitive Touch Sensor Breakout - MPR121: https://www.adafruit.com/product/1982 and I get always following error when I run the command: sudo python simpletest.py

Adafruit MPR121 Capacitive Touch Sensor Test
chmod: Zugriff auf „/sys/module/i2c_bcm2708/parameters/combined“ nicht möglich: Datei oder Verzeichnis nicht gefunden
Traceback (most recent call last):
File "simpletest.py", line 34, in <module>
if not cap.begin():
File "build/bdist.linux-armv7l/egg/Adafruit_MPR121/MPR121.py", line 90, in begin
File "build/bdist.linux-armv7l/egg/Adafruit_GPIO/I2C.py", line 79, in require_repeated_start
File "/usr/lib/python2.7/subprocess.py", line 540, in check_call
raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command 'chmod 666 /sys/module/i2c_bcm2708/parameters/combined' returned non-zero exit status 1

I testet it on a Raspberry Pi 3 Model B (4.9.31-v7+ #1007 armv7l GNU/Linux) and also on a Raspberry Pi Zero W (4.9.31+ #1007 armv6l GNU/Linux). Both devices are up to date (sudo apt-get update / upgrade / rpi-update, etc.) and running Raspbian and using Python.

All required dependencies as described on the page of the MPR121 tutorial https://learn.adafruit.com/mpr121-capac ... k/software are installed. I2C is enabled as described on https://learn.adafruit.com/adafruits-ra ... guring-i2c and the modules are loaded:

lsmod

rfcomm 37723 4
arc4 2211 0
ecb 2426 0
md4 3862 0
md5 2608 2
hmac 3252 2
bnep 12051 2
hci_uart 20020 1
btbcm 7916 1 hci_uart
bluetooth 365511 25 hci_uart,bnep,btbcm,rfcomm
nls_utf8 1656 2
cifs 422138 4
spidev 7373 0
brcmfmac 222874 0
brcmutil 9092 1 brcmfmac
cfg80211 543027 1 brcmfmac
rfkill 20851 5 bluetooth,cfg80211
spi_bcm2835 7596 0
bcm2835_gpiomem 3940 0
w1_gpio 4818 0
wire 32619 1 w1_gpio
lirc_rpi 9032 0
cn 5889 1 wire
fixed 3285 0
uio_pdrv_genirq 3923 0
uio 10204 1 uio_pdrv_genirq
snd_bcm2835 24427 0
snd_pcm 98501 1 snd_bcm2835
snd_timer 23904 1 snd_pcm
snd 70032 3 snd_timer,snd_bcm2835,snd_pcm
lirc_dev 10583 1 lirc_rpi
rc_core 24377 1 lirc_dev
i2c_bcm2835 7167 0
i2c_dev 6913 0
fuse 99603 3
ipv6

I'm wondering about the difference about the name of the loaded module i2c_bcm2835 and the name in the error-code "/sys/module/i2c_bcm2708/parameters/combined": no such file or directory.

And indeed there is no folder named i2c_bcm2708 in the /sys/module/ directory, only a folder named i2c_bcm2835:

/sys/module $ dir
8250 brcmfmac BANNED fuse keyboard module rfcomm snd_pcm uio workqueue
arc4 brcmutil debug_core hci_uart kgdboc mousedev rfkill snd_timer uio_pdrv_genirq xz_dec
auth_rpcgss brd dns_resolver hid lirc_dev netpoll rng_core soundcore usbcore
bcm2708_fb btbcm dwc_otg hmac lirc_rpi nfs scsi_mod spi_bcm2835 usbhid
bcm2835_gpiomem cachefiles ecb i2c_bcm2835 lockd nls_utf8 scsi_transport_iscsi spidev usb_storage
bcm2835_mmc cfg80211 fb i2c_dev loop printk sdhci spurious vc_mem
block cifs firmware_class ipv6 md4 rc_core smsc95xx sunrpc vt
bluetooth cn fixed kdb md5 rcupdate snd sysrq w1_gpio
bnep configfs fscache kernel mmcblk rcutree snd_bcm2835 tcp_cubic wire

The MPR121 board was found:

sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- 5a -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

And there is still an interesting fact: A few days ago I got my new Adafruit DC & Stepper Motor HAT for Raspberry Pi - Mini Kit https://www.adafruit.com/product/2348 and I installed it as described on https://learn.adafruit.com/adafruit-dc- ... g-software on the two raspberries and everything went fine without any problems and errorcodes.

So how to solve this problem, because I really want to use this 12-Key Capacitive Touch Sensor Breakout - MPR121 on my Pi's.

Thanks for your help!

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Guapa5000
 
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Joined: Wed Jun 14, 2017 8:11 am

Re: 12-Key Capacitive Touch Sensor Breakout - MPR121

Post by Guapa5000 »

SOLVED - I had to load the module i2c-bcm2708 additionally to the already loaded module i2c-bcm2835. And after doing this I got a new folder in the /sys/module/ directory named i2c_bcm2708. In this new sub subdirectory the missing file is shown:

/sys/module/i2c_bcm2708/parameters $ dir
baudrate combined

Now everything is fine without errors.

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adafruit_support_mike
 
Posts: 67391
Joined: Thu Feb 11, 2010 2:51 pm

Re: 12-Key Capacitive Touch Sensor Breakout - MPR121

Post by adafruit_support_mike »

Glad to hear you got it working. Happy hacking!

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887Flintnick
 
Posts: 5
Joined: Tue Jul 25, 2017 9:52 pm

Re: 12-Key Capacitive Touch Sensor Breakout - MPR121

Post by 887Flintnick »

Hey, I'm getting the same error message... could you please tell me a bit more about your solution?

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redwoodturner
 
Posts: 6
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Re: 12-Key Capacitive Touch Sensor Breakout - MPR121

Post by redwoodturner »

I'm having the same problem except all works well on Pi3 but not on a B+
The i2c_bcm2708 doesn't appear on either of them but works on the Pi3 without it. I see somewhere that the 2708 has been replaced with 2835. Any ideas?

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apoldion
 
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Joined: Fri Dec 29, 2017 3:22 pm

Re: 12-Key Capacitive Touch Sensor Breakout - MPR121

Post by apoldion »

Hello.
Can someone point me in the direction of how to resolve this issue please, or replacement code that implements the newer i2c_bcm283 ?

Cheers
Nick

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