Matrix user forums

Assumptions on Ver 3 Development Board


Hi Folks, Firstly thanks to Steve and Benj for there previous help. I am trying to get to grips with the development board which I am using with Flowcode Version. Can anyone please tell me if my following assumptions are correct or am I a million miles away.

1) There is no analogue input sensor connected to ARA3, because RA0 is connected to the light sensor, ARA1 is
connected to the potentiometer and ARA3 is connected to the Vernier socket.

2) RA4 – RA7 are not directly controlled by the PIC microcontroller. I don’t know how they could be controlled via this
expansion bus that Steve was discussing. I am not saying it can’t be, I’m saying I genuinely don’t understand if
someone could provide a simplified explanation I would be great full.

3) Although it has written in the data sheet that if an external input is
Applied via the screw terminals the push buttons should not be used as it could lead to unpredictable results. As
well as being unpredictable would that also be dangerous as you would have two separate voltages going into one
pin.

Again thank you in advance for all you help.

Jag.

Hello Jag

Thanks for the appreciation.

In response to your questions.

1) Yes this is correct the analogue pin that shares pin RA3 is connected to the vernier analogue sensor input.

2) Depends on the Microcontroller, some PICmicros have RA4 and RA5 pins, In this case these would be connected to the Switch and LED circuitry. The expansion bus provides direct access to these pins so if you have an external microcontroller sitting on your own board then you can use the expansion socket to program the PICmicro and also use the periperals on the dev board such as the Switches / LEDs or LCD etc.

3) Depends on the voltages but anything at 5V or under should be ok. An external switch could be used as long as you use the same method of resistor values for pull ups and pull downs as used for the main switches.

Hope this helps.