Comments for modelrail.otenko

Comment on OpenTTD on Dreamcast by stevenh

stevenh — Tue, 01 May 2012 01:21:07 +0000

Thanks for the offer, but I’ll pass… There’s enough information in this post and on the linked tt-forums.net thread if you’re keen.

Good luck!

Comment on OpenTTD on Dreamcast by VasiliyRS

VasiliyRS — Thu, 26 Apr 2012 19:26:31 +0000

Hello, what about updated to latest version port ?

Comment on Arduino + Controller Area Network (CAN) by Alex

Alex — Thu, 26 Apr 2012 07:59:46 +0000

Hi Steven.
Yes it’s the LCD on the RX on the lines between the MCP2515 and MCP2551 that’s flashing.
I am using your code to listen and not added anything atm untill I an reading the can.
Yes using Arduino UNO. Started a canbus topic on the Arduino forums. In Networking protocols and devices. Topic canbus a82c250.
Thanks for sorting will give it another session tonight.

Regards Alex

Comment on Arduino + Controller Area Network (CAN) by stevenh

stevenh — Wed, 25 Apr 2012 23:32:54 +0000

Alex,

Just to confirm, the Rx LED is on either the RX0BF or RX1BF pin? If it’s on the RX/TX lines between the MCP2515 and 2551 then that means the data is coming off the bus, but the controller isn’t reading it correctly.

By “how quickly” you’re trying to read the packets: if the loop in your code is too slow then there may be other packets transmitting across the network that your code is unable to read as your buffers are full. But if your buffer LEDs aren’t coming on, then it would mean that your MCP2515 isn’t actually receiving any messages off the CAN.

By “clearing values”: the frame buffer array that you are reading the data in to should be zero’d after the read to confirm that you are actually then reading in a new set of data.

Are you setting any masks or filters?
What does your init code look like? Your read/loop code? Are you using an Arduino?

Steven.

Comment on Arduino + Controller Area Network (CAN) by Alex

Alex — Wed, 25 Apr 2012 16:11:51 +0000

Hi
Having problem posting but here goes again.
Yes I am its a ROV with 2 nodes (topside and bottomside)
I have changed bits in the code for my bus speed which is 138.24
for this speed I am using a 11.0592 MHz crystal this zero error.
I have also changed the bit timing registers to CNF1 0×01 CNF2 0x0BA CNF3 0×07
Have tried all the modes. but the listen mode is main usage.
The question “How quickly are you trying to read the packets ” Not sure what you mean by this ??
The question “are you clearing the values read afterwards?” is this not done in the codeing ??
And yes I have LED on all.Only the Rx flashes
Regards Alex

Comment on Arduino + Controller Area Network (CAN) by stevenh

stevenh — Wed, 25 Apr 2012 00:02:14 +0000

Alex,

Are you reading another CAN network? Or do you have your own CAN setup? Ensure you have the correct timing for the network you are listening to.
What mode do you have your controller in? What speed? How quickly are you trying to read the packets and are you clearing the values read afterwards? Do you have LEDs on the TX/RX on the CAN side of the network? (Put LEDs on the RB0 and RB1 as per above)

Steven.

Comment on Arduino + Controller Area Network (CAN) by Alex

Alex — Tue, 24 Apr 2012 14:21:29 +0000

Hi
I cannot get mine to read the data.
It is reading the can but the data is not changing. Source is constantly changing.
Any suggestions.
Antony

Comment on Multiplexing ‘Photodetectors’ to detect train occupancy. by stevenh

stevenh — Mon, 09 Apr 2012 05:20:53 +0000

If you just want to use the Arduino as a throttle then look here:
http://modelrail.otenko.com/arduino/controlling-your-trains-with-an-arduino

Comment on Multiplexing ‘Photodetectors’ to detect train occupancy. by Barry

Barry — Mon, 09 Apr 2012 03:34:20 +0000

Hi good stuff, have you thought about doing speed control of the trains , i have an old ardunio that I used to use for photography, but i can’t programme

Barry

Comment on Arduino + Controller Area Network (CAN) by stevenh

stevenh — Sun, 25 Mar 2012 23:48:34 +0000

Randy,

Have you got LEDs on the buffer pins and on the TX/RX lines between the MCP2515 and MCP2551 to see what activity is happening?
Are you just tapping into the target CAN bus at a random location to see the data? Do you need to check where the terminators are on the line?
Have you got the TX/RX wires around the right way for the bus you are attaching to?
As long as your node is in Listen mode, then all should work… I’ve not actually attempted to plug onto a network, but I do have three nodes and have confirmed that the third can be in Listen mode and that it will watch packets flying around.

Since you’ve confirmed packet functionality in loopback mode, I’d imagine that your wiring to the MCP2515 is correct.

I can only guess that your baud rate for the CAN bus you’re connecting to could be wrong? I know that I had mismatched nodes previously and they don’t communicate at all. Note that if your crystal on your MCP2515 doesn’t match the crystals used on the network you are connecting to then you will need to do some maths The baud rate you pass during initialisation is calculated off the base crystal and must be a 100% match to the rest of the network. Can you confirm the speed of the target network?

I’ll re-download the code from above and confirm that changes I have made ‘offline’ and not compiled are, in fact, correct.

Comment on Arduino + Thermal Printers (Sparkfun, IBM 4160-TF6) by Pete

Pete — Fri, 23 Mar 2012 05:55:49 +0000

Hey Steven,

Thanks for your help! I will take a look.

Comment on Arduino + Controller Area Network (CAN) by RandyH

RandyH — Fri, 23 Mar 2012 02:09:45 +0000

Hi,
Awesome post really helped explain some areas that were hazy. I’ve spent about a week trying to interface with a working can bus and also with a single can device that is just sending out data. I’m unable to get the arduino with the MCP2515 to store anything to its buffer. When I check CAN.readstatus() it always returns a zero, I’ve also resetFiltersAndMasks() . Running everything in loopback works great. So I’m not sure where the issue is. I hooked up the can bus to an oscilloscope and the node I’m trying to read spikes at 2V where I can see the arduino outputting around 3V (by removing one from the bus). Also I tried adjusting the baudrate to see if that might be an issue, which didn’t seem to work.

I really appreciate any help and ideas on why the buffers arn’t storing data.

Thanks,
Randy

Comment on Arduino + Thermal Printers (Sparkfun, IBM 4160-TF6) by stevenh

stevenh — Thu, 22 Mar 2012 11:17:17 +0000

Pete,

I never did find a legit power supply for these printers. 24v was good enough though. If you can find two old PC power supplies or purchase a kit from jaycar then you should be fine. Jaycar also offers the ‘wall wart’ power supplies which should work. Just be careful of the ‘unregulated’ ones!

Steven.

Comment on Arduino + Thermal Printers (Sparkfun, IBM 4160-TF6) by Pete

Pete — Thu, 22 Mar 2012 10:43:26 +0000

Hey, I am looking at getting one of these off ebay, but these also don’t come with power adaptors. Did you ever manage to get one cause I have nothing I can jury rig that can supply that power.

Comment on Arduino + Controller Area Network (CAN) by stevenh

stevenh — Wed, 21 Mar 2012 23:10:33 +0000

Sounds like you’ve not downloaded the code at the bottom of my post? Instead you’ve used the code directly from Canduino where the “WProgram.h” reference is? I definitely do not have that reference in the ‘library’ that I have provided.

As for “Interrupts”… there is a configurable interrupt pin on the MCP2515, but this is simply brought to any digital out pin on the Arduino and brought high. As long as the Arduino keeps that pin high then the MCP2515 will not actually stall waiting for the interrupt to be cleared. I have defined that in the header for the library, yes, but it doesn’t need to hook to an actual Arduino interrupt.

Anyway, looks like you updated the Canduino library again and also got it to work

Comment on Arduino + Controller Area Network (CAN) by James

James — Wed, 21 Mar 2012 21:55:14 +0000

Sorry i meant WProgram.h (it was quite late when i commented ) And yeah for the nano according to the documentation SPI is only allowed on pins 10-13 and interrupts on pins 2 & 3. Maybe i was mistaken but i thought you had used interrupts in your original code, i thought the header file defined them…

Comment on Arduino + Controller Area Network (CAN) by stevenh

stevenh — Wed, 21 Mar 2012 09:52:45 +0000

James,

Glad you got this working… was heading home to compile my code when you sent this second comment. Interrupts on pins 2 & 3 hey? That’s got nothing to do with SPI? I haven’t actually used interrupts in my code but I imagine any of the libraries could require them.

I also can’t see where Window.h is included? I have definitely used my code here with Arduino 1.0

Steven.

Comment on Arduino + Controller Area Network (CAN) by James

James — Wed, 21 Mar 2012 05:07:20 +0000

Just to let you know it is working now without any problems. It seems the Arduino Nano only allows interrupts on pins 2 & 3. Also in order for the code to work with the latest Arduino compiler the include Window.h needs to be changed to include Arduino.h. In addition i got rid of the ifdef for different Arduino boards as i’m using two the same, and hardcoded one as TX and one as RX.

Thanks for the article it really helped me with my project

Comment on Arduino + Controller Area Network (CAN) by James

James — Tue, 20 Mar 2012 16:43:25 +0000

Hi, I tried your loopback code and i managed to get the RX: 0 / 0 / 0 / etc output with my circuit. Now the only difference in my circuit compared to yours is that I am using 8MHz oscillators to control the MCP2515 clock.

Now I have compiled your code for the guessing game and i just changed it so that one node is set as RX and the other TX. I get an output from the RX saying Guess has been set at: 8 and the TX is outputting the numbers it is guessing. However when it guesses 8 it doesn’t output I think I got it?: as it should and then switch positions with the RX node. Instead it keeps guessing as though it got it wrong. I would really appreciate it if you could help me as I am doing my project for university on the CAN bus and i need it working by thursday…

Thanks!

Comment on Arduino + Controller Area Network (CAN) by stevenh

stevenh — Tue, 06 Mar 2012 03:42:20 +0000

Thanks for the heads up… I’d realised the mistake and fixed it within a few minutes
The email that ended up in your inbox would’ve had the original error, as does your original comment!

I don’t even know if the __AVR_ATmega128__ is a valid target? Can’t find a ‘legit’ Arduino with this MCU.

Anyway, I’m currently in the process of expanding the code to support extended IDs and proper sending (finding a free buffer) and error handling.

Will update this post over the next few days.