Proto board memory?

M. K. Borri

I just got my 5-pack of proto boards (yay, nice and small!) one of which will end up piloting a solar-powered pontoon boat used to take water samples from various areas of a lake.

Quick question: The specs say it comes with a 64K rom chip... now I know we get about 32K of ram on the Prop, so is it safe to access the other 32K (with an i2c routine I guess) to do data logging and so on? I'd rather be told before I fry the chip by trying to talk to it [noparse]:)[/noparse]

Also, what's the overhead for the eeprom file? (as in, what's the first addresss I can peek/poke at on the rom chip -- somehow I doubt it's $8000, there usually is some padding...)

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http://forums.parallax.com/showthread.php?p=650217

meow, i have my own topic now? (sorta)

Mike Green

You can use the 2nd 32K anyway you want. The Prop chip loader and the Propeller Tool don't know about it ... They only access the first 32K.

There's no file system. You just have 32K of space that you can use as you want. The first address is indeed $8000.

There are several sets of I2C routines available. There are two sets in the Object Exchange and another that's part of the Propeller OS and FemtoBasic/BoeBotBasic (also in the Object Exchange). Any of them should work although some have had problems with "i2c Object and examples" when used with a boot EEPROM (like on the Protoboard).

Post Edited (Mike Green) : 5/28/2007 6:36:25 PM GMT

M. K. Borri

Super shiny, thanks! Now if I could only figure out how to build a h-bridge with the efficiency I want from it.... (right now I'm considering a hybrid, 2 relays "up" to switch forward/reverse with default being forward, and 2 n-channel trenchfets "down" to do pwm). Turns out that running stuff from solar gives a lot of headaches hardware wise [noparse]:)[/noparse] I need to either go with that, or make a headache-less charge pump for two more n-channel trenchfets to put on the upper half of the bridge, p-channels eat up a lot of power themselves... then i have to get the prop to drive all this... fun [noparse]:)[/noparse]

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http://forums.parallax.com/showthread.php?p=650217

meow, i have my own topic now? (sorta)