Installing Code for PiFace Real Time Clock

Hah! Thats just linux being pig headed, run the chmod command using sudo like below. The idea being that if a user doesn't have permission to execute a file then the system isnt going to confirm that files existence either so rather than saying permission denied, it just says file not found etc... It discourages repeat attempts at illegally executing files I think!

sudo chmod +x ./pifacertctest.sh

Ive just completed the steps of downloading using wget, then sudo chmod etc.. to test it out and can confirm it does work using sudo!

edit (the below is nothing to do with the question, its just some further reading!!)

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The chmod case can be quite confusing, if you are interested here is an explanation why we need to use sudo chmod in this case.

1) If we use chmod +x ./pifacertctest.sh the file becomes executable for the logged in user, on the raspberry pi that user is called "pi"

2) We need to execute the file using sudo ./pifacertctest.sh using sudo means we are no longer acting as the user "pi" but we are acting as the user "root" (or with root user privileges)

3) because the pifacertctest.sh has been made executable for the user "pi" and NOT the user "root" when we try and execute it with root priviliges (sudo), the root user doesn't have the executable permission

4) if we use sudo chmod +x ./pifacertctest.sh the file becomes executable for the root user, this is because we used sudo

5) Now the root user has permission to execute the file, its now possible to do with sudo ./pifacertctest.sh

6) if the script didnt need executing with root privileges (sudo) then we wouldnt have to sudo chmod.

Dear Ms. Tozer,

You were correct about permissions. The command sudo chmod +x ./install pifacertctest.sh apparently worked. I now have in my /home/pi folder
(in yellow gold)

install-piface-real-time-clock.sh
pifacertctest.sh
(among other files in blue)

The following is a rundown of the command line staements (Input) and replies (Output) within the teminal.

Input: ls /dev
Output: Many files, mostly ram##'s, alot of tty## 's, some vcsa#'s and loop#'s and another dozen.
(None that look like mcpXXXXXXX's ARMyyyyyyyy's or microprocessor names.)

Two positive returns:

Input: ls /dev | grep "i2c"
Output: i2c-1

Input: sudo i2cdetect -l
Output: i2c-1 i2c   20804000.i2c   I2C Adapter

Several replies showed failures:

Input: sudo systemctl start pifacertc
Output: (abreviated) Failed to start service, failed to load, and/or not found

Input: sudo systemctl start pifacertctest
Output: (abreviated) Failed to start service, failed to load, and/or not found

Input: sudo systemctl is-enabled pifacertc
Output: (abreviated) Failed to start service, failed to load, and/or not found

Input: sudo systemctl-a
Output: (abreviated) Failed to start service, failed to load, and/or not found

cat /proc/cpuinfo

ARMv7-comp processor rev 7
2.85
half .....
)x41
7
0x0
0xb76
7
BCM2708 (this may be an identifier)
900092    (this may be an identifier)
0000000070ec5112

in your screenshot on one of your replies

Input: /sys/class/i2c-dev/i2c-1/device/new-device
Output: no reply

I must tell you that within my /boot/config.txt file, both i2cand spi are enabled
dtparam=spi=on
dtparam=i2c_arm=on

can both be working simultaneosly?

Thats all I tried to do to up to this point.

I hope you understand the above and will be glad to do any other experiments
you put forth. Please ask questions. I believe the pifacertctest will eventually be successful.

However, at this point, I dont know how the integration of the github.com/piface/PiFace-Real-Time-Clock install can be invoked along with pifacertctest install since the naming between the two is different and the two code listings are inherently incompatible (maybe a poor word choice).  I wondered if you had an overall solution (vision) in mind.

Sorry for the bother and If you do not have time to continue, please tell me.
Thanks continually, Frank.

Im assuming that solving the i2c bus problem has not solved the situation of the clock working. Its going to be difficult to help troubleshoot further without actually have one of the rtc clock modules myself but here are some steps that I would take, im going to make a numbered list of things for you to try, could you reply with a corresponding numbered list accordingly please

I know that the install script I modified works as intended and creates the "driver script" on the raspberry pi, this much I have been able to confirm simply by running the script myself, so from this point please try:

1) Power off your raspberry pi and disconnect the piface rtc module, check to make sure that the battery on the module has power left in it and after a few minutes connect everything back up, once the raspberry pi boots back up type sudo hwclock -r please can you let us know the outcome of this. If its working, it should print a date/time to the terminal and if not it will display a problem communicating with the device

2) install i2c tools sudo apt-get install i2c-tools and then run sudo i2cdetect -y 0 and then run sudo i2cdetect -y 1 One of these will return an error, the other one, most likely the latter will print out everything thats present on the i2c bus, it would handy if you could cut and paste or even do a screen shot of the output for us.

What Im trying to do is establish whether your raspberry pi is capable of communicating with or seeing if the rtc clock module is identifiable by your raspberry pi, this will help work out if the error is on the rtc clock module itself or whether its on the raspberry pi. As I say its difficult to troubleshoot something that I dont have physical contact with so if you could follow these instructions it would help greatly to move forwards with it.

also, you got this part wrong in what you just posted

in your screenshot on one of your replies

Input: /sys/class/i2c-dev/i2c-1/device/new-device
Output: no reply

 

In the screen grab I effectively did(in a slightly different way):

cat /sys/bus/i2c/devices/1-006f/name

which should furnish you with a result once you have run the install script, the 1-006f part is the i2c address that the rtc clock module should be registered at, the name tells us the name of the module which is mcp7941x which is the microchip identifier on the rtc module.

Right now, Im more concerned with whether the rtc module is being identified rather than trying to debug the "driver" software, there could be many reasons for this so hopefully we can persevere!

Dear ms. tozer,

your messages were very clear. Ran all you asked and (in my own naïve opinion) quite negative results.

1,) Powered off RPi0.  Disconnected Ethernet module (enc28j60) and connections. I have WiPi operational on hub attached to RPi0.  Disconnected battery. Removed RTC module.  Removed Battery and verified output at 3.27 - 3.29 V.  Returned Battery and RTC module. Installed battery (plus side up) and affixed pins to holes snuglt and securely.  Rebooted.  At terminal, typed: sudo hwclock -r  (No date/time returned.)  Return:  hwclock: cannot access the hardware clock via any known method. hwclock: Use the debug option to see details of our search for any access method.  My try: Typed: sudo hwclock --debug  Return: hwclock from util-linux 2.25.2  hwclock: cannot open /dev/rtc : no such file or directory. No useful clock interface found  hwclock: cannot access the hardware clock via any known method.  My 2nd Try: (searched file manager). There is no file or directory at under: /dev  named  rtc.

2,) Typed: sudo apt-get install i2c-tools  Return: Reading packing lists ..Done  Building dependency tree Reading state information . . Done  i2c is already the newest version 0 upgraded 0 newly installed 0 to remove 0 upgraded  Typed: sudo i2cdetect -y 0  Return: Error: could not open file '/dev/i2c-0 or 'dev/i2c/0' No such file or directory Typed: sudo i2cdetect -y 1  Return: A matrix with 0 through 9 a b c d e f (across) 00:  through 70 9down) " 6f " at  60:  f all others -- .

As requested in your next post-  Typed:  cat /sys/bus/i2c/devices/1-006f/name  Return: no such file or directory.

In my pi directory, I still have the two files:

install-piface-real-time-clock.sh

pifacertctest.sh

I'm my humble opinion I don't know how to manage the GitHub PiFace-Real-Time-Clock and pifacertctest .sh  operations.

Your comments, thanks. Frank

Dear ms. tozer,

your messages were very clear. Ran all you asked and (in my own naïve opinion) quite negative results.

1,) Powered off RPi0.  Disconnected Ethernet module (enc28j60) and connections. I have WiPi operational on hub attached to RPi0.  Disconnected battery. Removed RTC module.  Removed Battery and verified output at 3.27 - 3.29 V.  Returned Battery and RTC module. Installed battery (plus side up) and affixed pins to holes snuglt and securely.  Rebooted.  At terminal, typed: sudo hwclock -r  (No date/time returned.)  Return:  hwclock: cannot access the hardware clock via any known method. hwclock: Use the debug option to see details of our search for any access method.  My try: Typed: sudo hwclock --debug  Return: hwclock from util-linux 2.25.2  hwclock: cannot open /dev/rtc : no such file or directory. No useful clock interface found  hwclock: cannot access the hardware clock via any known method.  My 2nd Try: (searched file manager). There is no file or directory at under: /dev  named  rtc.

2,) Typed: sudo apt-get install i2c-tools  Return: Reading packing lists ..Done  Building dependency tree Reading state information . . Done  i2c is already the newest version 0 upgraded 0 newly installed 0 to remove 0 upgraded  Typed: sudo i2cdetect -y 0  Return: Error: could not open file '/dev/i2c-0 or 'dev/i2c/0' No such file or directory Typed: sudo i2cdetect -y 1  Return: A matrix with 0 through 9 a b c d e f (across) 00:  through 70 9down) " 6f " at  60:  f all others -- .

As requested in your next post-  Typed:  cat /sys/bus/i2c/devices/1-006f/name  Return: no such file or directory.

In my pi directory, I still have the two files:

install-piface-real-time-clock.sh

pifacertctest.sh

I'm my humble opinion I don't know how to manage the GitHub PiFace-Real-Time-Clock and pifacertctest .sh  operations.

Your comments, thanks. Frank

Hi Frank,

The good news is, your 'pi is communicating with the RTC. The i2c-detect tool asked: "Is there anybody at 0x6F?" and the chip answered: "Yes, I'm here, go ahead what do you want?" (the i2c-detect tool then turns around and does nothing. Quite mean towards the I2C chip that was willing to help... :-) ).

You can follow my instructions at: Rtc - BitWizard WIKI

You've gotten the I2C bus up-and-running, so some stuff is no longer necessary. Start with:

modprobe i2c:mcp7941x

echo mcp7941x 0x6f > /sys/class/i2c-dev/i2c-1/device/new_device # For rev2 RPi

It seems that whomever made YOUR rtc was trying to do too much at once, possibly with some changes in raspbian that the automatic script wasn't prepared for....

Dear Mr Wolff,

Just got your message but I'm at a library. Trying to follow Ms Tozers instructions but I appreciate the great insight you have concerning RTC. I see you have a follow up reply which I will respond to after I get these instructions in line. I have got a couple questions 1. what does bcm2708 and mcp7941x refer to specifically and do these pertain to a RPi Zero (is it the same for a RPi Zero version 2). You mentioned rev 2 RPi  and rev 1 RPi,  are these pertaining to a RPi Model 2 rev 1 and 2 or RPi zero version 1 and 2 or does it matter? My present concern is with an RPi Zero ver 1 but I will install an RPi Zero ver 2 in the future after resolving problems. I also have an RPi 3 which I want to install an RTC. Sorry for the questions but I'm getting more involved with these devices. Finally, the Rtc - BitWizard WIKI, is that a forum specifically tor RTC's ? Finally the end of this forum states the Source: http://www.element14.com/community/message/63885. This is very difficult to understand (I don't think I need to know it ) but is this forum separate then the one I'm on ?

Your support is well taken.

Thanks, Frank