netstranger.nz
- 26th March 2010, 18:48
Hi Everyone
Here are some of the hardware I found useful for the hobby projects.
Pics:
I use 12F683 and 18F1230.
12F683 (Farnell p.n. 1579577) is a small 8pin chip with 8MHz internal oscillator, A/D and PWM. I just found it is not always needed to have a 40 pin monster. See 12F683_Examples.pbp and 12F683 Config.jpg
18F1230 (Farnell p.n.1332230) is an 18pin chip with 32MHz internal oscillator A/D and PWM. See 18F1230_Examples.pbp and 18F1230 Config.jpg
Power Supply:
I use LM7805 (Farnell p.n. 1102157) where possible. The problem with it is heat dissipation. Dropping voltage from 12v and drawing around 100mA (PIC + LCD) is it’s maximum because I can’t touch the heatsink. I think it is not suitable for battery powered applications. See LM7805.jpg
As an alternative LM2574 (Farnell p.n. 1460659) is 40 – 7vIN 5v 500mAOUT buck converter. See LM2574.jpg
RS232:
I found serial data communication to be very useful. See RS232.jpg for schematics. It is very hard to find a computer with a series port nowadays. So I use USB to Serial Converter. It makes your project USB compatible :) .
A/D Converter:
I think it is great to have A/D onboard. The only two problems I see is measuring say 12v and self powering of the PIC through the A/D pin when PIC’s power is off (say you measure voltage of independent power source). I used series resistor to overcome the self powering and voltage divider to measure 12v. See AD.jpg
Driver:
You can’t drive much with the PIC itself. Here is the MOSFET that I use (Farnell p.n. 9935657). It is 5v driven and doesn’t require heat sink on the currents lower than 10A. It is also internally protected from over voltage (with a zenner diode that will heat if it conducts excessive voltage repeatedly i.e. switching an inductive load repeatedly) so you will be better off with using it’s internal zenner and putting it on the heatsink(if needed) than using an external one. See Driver.jpg
TVS:
5v TVS is optional (Farnell p.n. 1017811). It is used because MCLR doesn’t have over voltage protection(to allow programming at 8v).
Schottky:
Farnell p.n. is 1365072. It is used with A/D to remove negative voltage from
RS-232 IN pin.
This is it :). Please use MicroCodeStudio with *.pbp . Different sections of *.pbp are separated by ’======. Don’t compile the whole file at once.
If you know some interesting hardware please reply .
Here are some of the hardware I found useful for the hobby projects.
Pics:
I use 12F683 and 18F1230.
12F683 (Farnell p.n. 1579577) is a small 8pin chip with 8MHz internal oscillator, A/D and PWM. I just found it is not always needed to have a 40 pin monster. See 12F683_Examples.pbp and 12F683 Config.jpg
18F1230 (Farnell p.n.1332230) is an 18pin chip with 32MHz internal oscillator A/D and PWM. See 18F1230_Examples.pbp and 18F1230 Config.jpg
Power Supply:
I use LM7805 (Farnell p.n. 1102157) where possible. The problem with it is heat dissipation. Dropping voltage from 12v and drawing around 100mA (PIC + LCD) is it’s maximum because I can’t touch the heatsink. I think it is not suitable for battery powered applications. See LM7805.jpg
As an alternative LM2574 (Farnell p.n. 1460659) is 40 – 7vIN 5v 500mAOUT buck converter. See LM2574.jpg
RS232:
I found serial data communication to be very useful. See RS232.jpg for schematics. It is very hard to find a computer with a series port nowadays. So I use USB to Serial Converter. It makes your project USB compatible :) .
A/D Converter:
I think it is great to have A/D onboard. The only two problems I see is measuring say 12v and self powering of the PIC through the A/D pin when PIC’s power is off (say you measure voltage of independent power source). I used series resistor to overcome the self powering and voltage divider to measure 12v. See AD.jpg
Driver:
You can’t drive much with the PIC itself. Here is the MOSFET that I use (Farnell p.n. 9935657). It is 5v driven and doesn’t require heat sink on the currents lower than 10A. It is also internally protected from over voltage (with a zenner diode that will heat if it conducts excessive voltage repeatedly i.e. switching an inductive load repeatedly) so you will be better off with using it’s internal zenner and putting it on the heatsink(if needed) than using an external one. See Driver.jpg
TVS:
5v TVS is optional (Farnell p.n. 1017811). It is used because MCLR doesn’t have over voltage protection(to allow programming at 8v).
Schottky:
Farnell p.n. is 1365072. It is used with A/D to remove negative voltage from
RS-232 IN pin.
This is it :). Please use MicroCodeStudio with *.pbp . Different sections of *.pbp are separated by ’======. Don’t compile the whole file at once.
If you know some interesting hardware please reply .