MAX133 Interface to PIC16F877, how to?

[phreakerzoid]

This is my first post please make it easy on me. Here it goes.

I need help, ideas, plans, schematics, codes on how to interface MAX133 which is a 3 3/4 Digit DMM Circuit from Maxim. I'm planning to build a remote voltage monitoring system which will send data via two (2) HAC-UM96 RS-232 Module to display it on a VB6 written gui. I will having no problem within the VB side just with the MAX133 interface. This system will become a part of a remote operated robot. I've read the MAX133 datasheet but it is still cloudy in my head.

The datasheet is available here:
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1289

Thanks in advance.

[skimask]

My advice...
Get rid of the MAX133 (way too much unusable, unneeded stuff there), use a PIC with an onboard A/D converter, send that output over the serial link and reconvert the results at the PC, or convert the results to a voltage value at the PIC, doesn't matter. I mean, how much accuracy do you REALLY need? If you use a PIC with a 12bit A/D converter, that'll give you 3mV of resolution with a 12v Vref (but since the PIC will only handle 5v, you'll have to use a voltage divider, still you get 1.2mv of resolution).

[phreakerzoid]

Thanks for the advice skimask, however, I still wanted to make this system separate or independent from the main control system so that the main control will have no codes about the A/D conversion and Serial transmit of the voltages that I will be monitoring. Accuracy is really not a problem but the number of available A-D pins available on a 16F877, I will be needing at least 10 available pins to do this completely. The following components are going to be monitored by this system.

*Lights Voltage Supply (6V)
*Servo Voltage Supply (5V)
*Main Voltage Supply (12V)
*Receiver Voltage Supply (9V)
*Transmitter Voltage Supply (9V)
*Drive Motor Voltage Supply (7.2V)
*Water Pump Voltage Supply (7.2V)
*Microcontroller (Main) Voltage Supply (5V)
*Sensors Voltage Supply (5V)
*Wireless RF Camera (9V)

Each component will depend on the Main Supply which is 12V and then converted to specific voltage using fixed voltage regulators except for the drive motors, pump, receiver/transmitter and camera.

If you have any idea on how to do this I would greatly appreciate your time and concerns.

[skimask]

I still wanted to make this system separate or independent from the main control system so that the main control will have no codes about the A/D conversion and Serial transmit of the voltages that I will be monitoring. Accuracy is really not a problem but the number of available A-D pins available on a 16F877, I will be needing at least 10 available pins to do this completely.

16 channel 12 bit A/D converter with a serial output. I don't have the part number off the top of my head, but I know they exist...and surely they're a LOT easier to use than that MAX133. Search Digikey, Mouser, whatever, they're out there...

And make it easy on yourself, learn PBP (the long way, not the short way), take a PIC18F4620 (13 channels of A/D), read the voltages (which need to be divided down using a simple voltage divider resistor network, in fact, just divide everything by 3 to make it easy), preconvert the numbers in the PIC if neccessary (i.e. if you want the output to read something like 4v, 3v, whatever) and send the data out serially on another pin.
And I don't see why this would be so complicated that you couldn't just integrate this into your main project rather than have it on another chip entirely...
All done very easily in PBP

[phreakerzoid]

skimask, thanks again for the advice, the only part that is available and closest to your suggestions on my nearest electronics supply store are MAX186 and MAX188, just read their datasheet and they are both Low-Power, 8-Channel, Serial 12-Bit ADCs the only difference is the Reference the MAX186 has an Internal Reference of 4.096V and the MAX188 has an External Reference. Which of these two could suit my application? and How can they be operated within the PBP?

If this is what I'll be using I guess I have to buy two of these or maybe just use two PORTA pins of the 16F877 and remove two IR sensors (GP2D12) from the robot and build an IR Sensor which could output digital 1 and 0 signals from scratch and connect them to an available Digital I/O pin.

[skimask]

skimask, thanks again for the advice, the only part that is available and closest to your suggestions on my nearest electronics supply store are MAX186 and MAX188, just read their datasheet and they are both Low-Power, 8-Channel, Serial 12-Bit ADCs the only difference is the Reference the MAX186 has an Internal Reference of 4.096V and the MAX188 has an External Reference. Which of these two could suit my application? and How can they be operated within the PBP?

If this is what I'll be using I guess I have to buy two of these or maybe just use two PORTA pins of the 16F877 and remove two IR sensors (GP2D12) from the robot and build an IR Sensor which could output digital 1 and 0 signals from scratch and connect them to an available Digital I/O pin.

Where did you get your PBP at?
And I'd still not even mess with the MAXxxx chips and just use a PIC.
But if you're hellbent on using them, you answered your own question...
The MAX186 have a serial output, so use the PICs serial input...

[phreakerzoid]

Where did you get your PBP at?

I bought it here locally for almost double the original price when converted to our currency. I guess its the product of taxes, duties, import/export etc. That made it that high. However, I find it a good investment because of its capabilities and the "easy learning" factor drove me to buy it. I also have a BS2 and BS2P40 both bought double the price from the original price when converted. PIC is hard to find in here only those that are most applicable are available such as the 16F628, 16F877, 18F242 and the 16F84 most the MCUs available here are Atmel and Zilog based. I've sticked to the PICs because of their Flash capabilities and an easy ICSP programming mode.

I just found something on the net and its a MAX186 interface to BS2, its actually my first time to try this device. I guess I have to test it on my BS2 first and then learn how it operates so that I could incorporate it to the PIC. This is the best thing about PBP it is compatible with the BS2 so I only have one software to work on both.

Thanks again for the reply skimask.