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Higher Engineering Science Assignment 2019/20

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I can't quite remember. I remember switching Rf and Ri values in order for the output voltage being +2.5. I think I also switched the positions of the sensors which resulted in a positive output.

Did you not add a inverting amplifier?

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Reply 21

justadumbboi

Original post by HuBeeny

I can't quite remember. I remember switching Rf and Ri values in order for the output voltage being +2.5. I think I also switched the positions of the sensors which resulted in a positive output.

Did you not swap the resistors to get -2.5 volts and then add a inverting amplifier?

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Reply 22

HuBeeny

Original post by justadumbboi

Did you not add a inverting amplifiier?

I think there are probably many acceptable answers. The inverting amplifier, if works, sounds right but switching them round felt simpler to me haha. As for amendments, one of them was definitely changing the values and getting a positive value. The others I can't quite remember. I'm curious as to what people thought about the pin table as it says pin one is set switch and the other is the realease. This is switched tho in the diagram. I assume these assignments have been cross-checked so it's probably not a mistake. I just don't see how it adds to the problem - it works when you take it to be correct in the diagram which is what it asks to copy and then amend.

Reply 23

collyn234

Hey all, I have half way through my assignment and kn Task 3a I am getting a pin type mismatch for the analogue pin input, I have a potential resistor that can be changeable on the value of resistance. My first flowchart decision went through good but it is this pin type mismatch that I am confused with. I have added the prefix "a_nameofinput" onto the analogue input and it still does not work for some reason. I think I am ok with Task 1 but unsure what to switch or make amendments to so that the voltmeter is 0v on the first test and then +2.5V on the second test.

Any advice would be much appreciated! Thank you.

Reply 24

HuBeeny

Original post by collyn234

What sim software are you using? To get it +2.5V you have to work out the AV and then pick corresponding R values. To get it +ve, you have to switch the pins on the OP AMP or add an AV1 inverting op-amp or something like that.

Reply 25

collyn234

Original post by HuBeeny

What sim software are you using? To get it +2.5V you have to work out the AV and then pick corresponding R values. To get it +ve, you have to switch the pin on the OP AMP or add an AV1 inverting op-amp or something like that.

I am using Yenka Simulation Software.

Reply 26

HuBeeny

Original post by collyn234

I am using Yenka Simulation Software.

Hmmm, I've never had that before. Did you change the pin type on pin0 to analogue? And did you connect up the potentiometer to the chip correctly? Also for the flowchart did you set the correct condition (analouge0 > 200) or whatever it was?

Reply 27

collyn234

Original post by HuBeeny

I connected up the potentiometer to the input correctly from what I remember, the input I was using was at the bottom of the microcontroller. I changed the flowchart to analogue > 200 but did the question not say to amend it so that 2V can be 100 and 4V be 200? I tried changing the analogue input from digital to analogue but found difficulty in doing so; the software told me it was a pin type mismatch which I can only assume as being a pin is mismatched with the input it is receiving, I have never used the software till I started the course.

Thank you for the help.

Reply 28

HuBeeny

Original post by collyn234

Hmm, the 2/4V is just a guideline I used it to connect a voltmeter across to check whether it was at 200 ect. I believe only input 0 can be changed to an analogue.

Reply 29

collyn234

Original post by HuBeeny

Hmm, the 2/4V is just a guideline I used it to connect a voltmeter across to check whether it was at 200 ect. I believe only input 0 can be changed to an analogue.

Ok, I will try and change my microcontroller settings to allow for a pin0 so that I can have an analogue input.

Thank you for your help and will let you know how I get on.

Reply 30

collyn234

Hello HuBeeny,

I have finished task 1, just need to do 1e which seems easy enough. Task 3, I am getting a type mismatch for x+1 then x = 10? for the looped 10 times condition. It is when the microcontroller flashes the lights 10 times. I understand what it could be and maybe I could use a loop process but that would make my flowchart too big to fit into the one file. Any suggestions?