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by edo1
Mon Jun 20, 2016 8:32 pm
Forum: Automation, sensing and robotics
Topic: Can someone recommend a popular GSM modem?
Replies: 13
Views: 12158

Re: Can someone recommend a popular GSM modem?

If I use your method, how do I hang up the modem to save bandwidth? I've read about some scripts that do "pon and poff" to turn on and off ppp over the modem. there are a lot of ways, e.g. you could use "ifdown usb0", "ifup usb0". but I'm pretty sure you shouldn't hangup modem, linux system doesn't...
by edo1
Mon Jun 20, 2016 8:13 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Source for CSI-2 ribbon connector
Replies: 5
Views: 956

Re: Source for CSI-2 ribbon connector

there are inexpensive cables on aliexpress.
I tested 60cm cables for about $3 each and they are working flawlessly for me.
by edo1
Mon Jun 20, 2016 6:32 am
Forum: Automation, sensing and robotics
Topic: Can someone recommend a popular GSM modem?
Replies: 13
Views: 12158

Re: Can someone recommend a popular GSM modem?

So if I understand correctly, your Huawei modem is a ttyUSB device on the RPI so it doesn't need any "driver". If you need internet connection only, you could use "NIC mode". You do not need any additional software tuning, only few lines in /etc/network/interfaces allow-hotplug usb0 iface usb0 inet...
by edo1
Sun Jun 19, 2016 2:24 pm
Forum: General discussion
Topic: Trusted Boot of RPi 2B
Replies: 17
Views: 4267

Re: Trusted Boot of RPi 2B

zfyseu wrote:I have got two ideas to enhance the security of RPi
Which goal do you want to achieve?
What exactly does "enhance the security" mean?
by edo1
Sat Jun 18, 2016 8:32 am
Forum: Advanced users
Topic: Cross compile kernel module
Replies: 13
Views: 6158

Re: Cross compile kernel module

What am I doing wrong ? kernel version on the RPI seems to be different. You can install cross-compiled kernel and modules to raspberry. mkdir -p /tmp/to-rpi/boot make -j 6 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage ./scripts/mkknlimg arch/arm/boot/zImage /tmp/to-rpi/boot/kernel7.img make -...
by edo1
Sat Jun 18, 2016 8:08 am
Forum: General discussion
Topic: Trusted Boot of RPi 2B
Replies: 17
Views: 4267

Re: Trusted Boot of RPi 2B

RPI does not have any persistent memory available to user so you cannot configure it. All configuration is stored on the microsd card and it is impossible to forbid booting from untrusted card.
by edo1
Fri Jun 17, 2016 11:05 pm
Forum: Compute Module
Topic: Frequent filesystem corruption (Raspbian)
Replies: 8
Views: 1771

Re: Frequent filesystem corruption (Raspbian)

IMHO you problem is related to the GSM module. Isn't your GSM module or antenna located to close to RPI (or another electronics)? Is your power supply good enough? If low cellular signal occurs then current consumption of GSM module could be high and EMI could be high too (especially during GPRS/EDG...
by edo1
Wed Jun 15, 2016 9:47 am
Forum: Advanced users
Topic: Read from RS485 port
Replies: 4
Views: 3024

Re: Read from RS485 port

which hardware do you use for rs485 communications?
AFAIK rs485 is not supported with amba uart.
by edo1
Mon Jun 13, 2016 5:09 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI1 controlling MCP2515
Replies: 1
Views: 1360

Re: SPI1 controlling MCP2515

you can modify existing overlays: https://github.com/raspberrypi/linux/blob/rpi-4.4.y/arch/arm/boot/dts/overlays/mcp2515-can0-overlay.dts https://github.com/raspberrypi/linux/blob/rpi-4.4.y/arch/arm/boot/dts/overlays/mcp2515-can1-overlay.dts more info about DT overlays: https://www.raspberrypi.org/d...
by edo1
Fri Jun 03, 2016 8:58 am
Forum: Automation, sensing and robotics
Topic: Simple temperature sensor project
Replies: 6
Views: 1777

Re: Simple temperature sensor project

Stoo wrote:push notifications to my phone
you may want to use telegram for notifications
https://core.telegram.org/bots/api
by edo1
Sun May 29, 2016 9:31 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: [quick-guide] CAN bus on raspberry pi with MCP2515
Replies: 146
Views: 197719

Re: [quick-guide] CAN bus on raspberry pi with MCP2515

laalex wrote:if the can bus shield is not attached to any can, should the raspberry PI detect the can0?
yes.
by edo1
Sun May 29, 2016 8:59 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: [quick-guide] CAN bus on raspberry pi with MCP2515
Replies: 146
Views: 197719

Re: [quick-guide] CAN bus on raspberry pi with MCP2515

laalex wrote:Or to test a restart is required for every time I try a new wire configuration?
you could do

Code: Select all

rmmod mcp251x; modprobe mcp251x
to check without rebooting.
by edo1
Sun May 29, 2016 8:16 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: [quick-guide] CAN bus on raspberry pi with MCP2515
Replies: 146
Views: 197719

Re: [quick-guide] CAN bus on raspberry pi with MCP2515

I don't see a mcp2515 being mentioned as registered can interface. Only virtual can (vcan)... current kernel prints nothing about mcp2515 initialization failure/success. Here is a diagram for my circuit. The software is fine. I have everything required plus the vcan is working perfectly. Do You see...
by edo1
Fri May 27, 2016 9:48 am
Forum: C/C++
Topic: Polling serial data using... interrupts?
Replies: 11
Views: 3481

Re: Polling serial data using... interrupts?

even blocking IO won't produce noticeable CPU usage.

I could imagine only one way to make CPU busy: use non-blocking read with continuous polling.
by edo1
Wed May 25, 2016 9:30 pm
Forum: Troubleshooting
Topic: MCP2515 SPI setup
Replies: 12
Views: 6025

Re: MCP2515 SPI setup

I have tried to boot rpi without mcp2515 connected.
mcp251x module is loaded, but no can0 inteface and no "driver" symlink in /sys/bus/spi/devices/spi0.0/

So I suppose you have some wiring issue.
by edo1
Tue May 24, 2016 10:35 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: 1-wire Temperature Inaccuracy
Replies: 9
Views: 1466

Re:

Is there any chance of self-heating in your setup? I observed some self-heating in parasite power mode (5/16°C after 40 seconds of repeatable temperature reads). I have temp measurement running with a DS18B20 on GPIO. I gives a temp measurement but after checking it is about 1 to 1.5 degrees C high...
by edo1
Tue May 24, 2016 9:40 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: 1-wire Temperature Inaccuracy
Replies: 9
Views: 1466

Re: 1-wire Temperature Inaccuracy

rpiho wrote:the problem is with the way the Pi's modules calculate the temp.
there are two lines of code, you could check them for yourself
http://lxr.free-electrons.com/source/dr ... erm.c#L186
by edo1
Tue May 24, 2016 9:31 pm
Forum: Troubleshooting
Topic: MCP2515 SPI setup
Replies: 12
Views: 6025

Re: MCP2515 SPI setup

RaviTG123 wrote:Why does 'driver' show up in my /sys/bus/spi/devices/spi0.1 but not in spi0.0??
I'm puzzled.
What does "ls -l /sys/bus/spi/devices/spi0.1/driver" show?
by edo1
Tue May 24, 2016 2:21 pm
Forum: Troubleshooting
Topic: MCP2515 SPI setup
Replies: 12
Views: 6025

Re: MCP2515 SPI setup

dtoverlay=mcp2515-can0,oscillator=16000000,interrupt=25 Note here the use of a colon (:) to separate the overlay name from its parameters, which is a supported syntax variant. https://www.raspberrypi.org/documentation/configuration/device-tree.md so you need to use dtoverlay=mcp2515-can0:oscillator...
by edo1
Sun May 22, 2016 9:00 pm
Forum: Русский
Topic: RT kernel + драйвер тача 5"
Replies: 1
Views: 989

Re: RT kernel + драйвер тача 5"

ищите исходники для вашего тачскрина, это не подойдёт:
https://github.com/saper-2/rpi-5inch-hd ... een-driver
?
by edo1
Sat May 14, 2016 10:06 am
Forum: Automation, sensing and robotics
Topic: Using Raspberry Pi as an ALU for data acquisition system
Replies: 8
Views: 1111

Re: Using Raspberry Pi as an ALU for data acquisition system

Zbachir wrote:We need a controller that is capable of using the seriel communication "SPI, I2C, and, UART".
rpi could be spi and i2c master, not slave (indeed slave is possible too, but is not so easy)
by edo1
Thu May 05, 2016 6:35 pm
Forum: Troubleshooting
Topic: Doing CAN using mcp2510
Replies: 11
Views: 2283

Re: Doing CAN using mcp2510

I have no issues with raspberry 4.4 tree (and mcp2515, but it shouldn't matter), could you check it?
by edo1
Thu May 05, 2016 5:57 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: [quick-guide] CAN bus on raspberry pi with MCP2515
Replies: 146
Views: 197719

Re: [quick-guide] CAN bus on raspberry pi with MCP2515

Can(!) can-utils only deal with two can-controllers? SPI+CE0 and CE1? can-utils has nothing to do with can controllers count, but you need kernel support. there was information that (with correct DT overlay) it is possible use any GPIO pin as chip-select (so you could have more than two SPI slaves).

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