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Forum Index : Microcontroller and PC projects : Using i2c on Micro Mite
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| MOBI Guru  Joined: 02/12/2012 Location: AustraliaPosts: 819 |
Here I go banging on about i2c again. I just thought I'd start a thread so members can share how they use I2C. This is just an example. I took Geoff's i2c RTC example for Maxi/Mini and displayed the time and date to a LCD. Plug in the Keypad and use it to change the date/time settings or drive a menu or with a data expander, manually or automatically switch relays etc. The Chinese RTC shown also has temperature readings available plus a pad for a eeprom. 
David M. |
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
WOW - we've gone back in time!  Smoke makes things work. When the smoke gets out, it stops! |
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| MOBI Guru Joined: 02/12/2012 Location: AustraliaPosts: 819 |
You weren't supposed to notice the date. I'll plug the keypad in and programme it to alter the date and time (the alarm functions can also be altered). Next edition. David M. |
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MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
Is that a powered i2c 'hub'? 
Microblocks. Build with logic. |
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| MOBI Guru Joined: 02/12/2012 Location: AustraliaPosts: 819 |
Hi TZA, yes. The i2c bus board (4 pin headers) is fed with either 5vdc or 3.3vdc from a small LM317 power supply fed from a 5vdc switch mode plug pack. I plugged the Keypad in last night, but the base address I had chosen a few years ago couldn't be recognised by the uMite i2c commands as the address range was illegal, so I had to reflash the keypad PIC (F88) with a legal address. So far, the code lets me interrupt the main programme by polling the keypad in the main programme loop on the way past and also to read two keys (ascii format) and produce a bcd byte as required by the time/date registers of the rtc. I'll post the full code when I get it all running. David M. |
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| MOBI Guru Joined: 02/12/2012 Location: AustraliaPosts: 819 |
Traps for beginners. Don't assume all RTC chips have the same register layout. I couldn't understand why the "day of the month" wouldn't change under Keypad control. The chip I'm using has a day of the week in between. It works now. At the moment the register numbers and BCD register codes are displayed on the terminal. The date and time is on the LCD. I'll change that to fully LCD before I post my results. Also a couple of minor glitches to pretty up. This set up should be handy for anyone wanting to make a timer solar tracker. The key pad makes it easy to reset daylight saving etc without having to alter the programme. Also to switch things on and off at the controller and to alter timer periods etc. David M. |
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| MOBI Guru Joined: 02/12/2012 Location: AustraliaPosts: 819 |
If anyone wants a play. @Grogster, we are in the right year now. The test set up is essentially a clock running in a loop. The keypad is polled at the top of the loop and drops out to a menu subroutine to alter the registers then back into the loop. 
Plus example firmware in zip. If you are using your own i2c modules, addresses and formats may change a bit. 2014-02-09_093854_uMite_rtc_keypad_lcd_test.zip David M. |
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