RE: [Raspberry_Pi_4-Ham_RADIO] Re: PI TNC Availability
- Max,The TNC draws very little - around 5 mA., and although the logic runs at 3.3 V, it is fed fron the 5V supply via an on-board requlator. The main problem with power on the PI is that the USB ports are very limited (at least on the version 1 - with the verrsion 2 boards the current limiters have been removed). I dont't think there is a problem with power on the 26 way header. In fact the board can be powered via the header rather than the micro usb port, and with version 2 boards it can be powered via the USB ports.The I2C bus supports up to 62 addresses, and you run a copy of the driver for each board, so the number that can be stacked is only limited by capacitive load on the I2C bus. I've only run two, but I don't think there will be a problem with more. I only have two of the TNC-X boards, but I have three similar boards fitted with RFM22 UHF tranceiver modules - I when I have a bir of spare time I'll set up a 5 board stack and see how it goes.The I2C is handled by the PIC - I'm using the 16F1747, which has I2C support.73, John
From: Raspberry_Pi_4-Ham_RADIO@yahoogroups.com [mailto:Raspberry_Pi_4-Ham_RADIO@yahoogroups.com] On Behalf Of Max
Sent: 05 January 2013 02:24
Subject: [Raspberry_Pi_4-Ham_RADIO] Re: PI TNC Availability
John, have you measured the current draw of the new TNC-X? I know the PI is sensitive to voltage and some devices draw more current than the PI could supply reguardless of how large the power supply is. I was curious how many of the new TNC-X's could be stacked before power became a problem. Also, how many I2C addresses can they be set for? How many address will your driver handle? What chip are you using to provide the I2C to serial conversion.
Thanks, Max KG4PID
- Hi folks.The pi port of BPQ32 is about ready for testing. There are sure to be problems with it still, but if anyone is willing to try it please let me know. At least to start, I suggest testers should be familiar with BPQ32, and have a basic knowledge of linux commands - this isn't really something for those new to either BPQ or linux to play with at this stage.The basic features are:Has been tested on Raspberry PI and Ubuntu running on a PC.BPQ32 compatible Node, includng the APRS Digi/Igate featureUses standard bpq32.cfgDrivers for KISS, AXIP, BPQEther, Telnet, SCS Tracker, SCSPTC. I2C Driver for PITNC on the PI. Others to follow.Includes the BBS part of BPQMailChat (not chat).BBS Configuration and BBS/Node monitoring via a Web interface.The instructions for installing BPQ on linux can be downloaded from https://dl.dropbox.com/u/31910649/InstallingLINBPQ.htm73,John G8BPQ