I2C Monitor– Implementation and Limitations The implementation is shown on the next figure. For the quick prototype, the FTDI interface was replaced with the FTDI TTL cable. The implementation worked as expected with two caveats; the maximum bus supported speed is 100kHz, and if the internal buffer on the MCU overflows there is currently no indication for this. I was hoping to be able to operate up to 400kHz, but it’s not happening. Since this is good enough for what I targeted originally, it will suffice until next time. It looks like this is better suited for an FPGA application – live and learn I guess. Code is written in Oshonsoft Basic. i2c monitor.png Code Code : 'Author: languer (©2012) 'Pin Allocation: 'PIN# Main_Fn Secondary_Fn 'RA0 -> not used 'RA1 -> not used 'RA2 -> not used 'RA3 -> not used 'RA4 -> not used 'RA5 -> ...
'Author: languer (©2012) 'Pin Allocation: 'PIN# Main_Fn Secondary_Fn 'RA0 -> not used 'RA1 -> not used 'RA2 -> not used 'RA3 -> not used 'RA4 -> not used 'RA5 ->
I2C Monitor – Concept I came across an issue where some I2C communications between an FPGA and an EEPROM was giving troubles. The FPGA acted as controller between the software and the rest of the hardware; so there were two components to the issue: (1) software communications to the FPGA, and (2) I2C communications between the FPGA and EEPROM. I’m simplifying here of course, but that pretty much summarizes the issue. This I2C EEPROM was accessed every time the hardware power-up, and all its content was “read” by the FPGA (and passed on to the software). As luck would have it, every now and then something would be dropped on the communications. To isolate it a Logic Analyzer was used (and a lot of time). During all that I though; men it would be great if I had a monitor for the I2C communications, and one that can log for that matter. It probably wouldn’t have helped much in this case – but there were some other issues that were associated with this, which having such a tool ...
I’ve been looking at a simple way I can “play” and “monitor” several gadgets on my router/printer/etc room through any pc on the house. I looked at using wireless modules of different frequencies/technologies (ISM/433MHz, Zigbee, …); all would require specific hardware at each of the PCs … not quite what I had in mind. Around came two things which seemed to be “better”: The Wifly module from Roving Networks (e.g. Wifi Garage Door Opener) and the WIZ110SR module Wiznet. The Wifly module looked pretty cool, and the garage door application example I looked through was nothing short of cool. However although I am quite capable with hardware, I am not quite savvy with Ethernet stuff (you know protocols, etc). So when I looked at the WIZ110SR and saw that I could do simple RS232-to-Ethernet (telnet) communication with it I figure I could possibly start with that. So I order one along with a +5VDC wall-wart. Here’s how it went… Remember I mentioned I’m no expert ...
