can you run a Microcontroller off a Microcontroller - Page 1
Forum section: electronics / general

author: jaRON
author_rank: Contributor
timestamp: September 28, 2011, 07:10:32 am
content: can you run a Microcontroller off a Microcontroller

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 28, 2011, 07:23:39 am
content: can

author: jaRON
author_rank: Contributor
timestamp: September 28, 2011, 07:25:40 am
content: Can i get more info like how

author: Psi
author_rank: Super Contributor
timestamp: September 28, 2011, 07:30:15 am
content: Depend how you mean, you can code a microcontroller to respond to commands from another microcontroller using a link between them (serial, spi, etc, or invert your own link).You can even program one microcontroller to reprogram another microcontroller on demand.There are quite a few ways of "running a Microcontroller off a Microcontroller"You could even program one microcontroller to pretend to be a memory chip (with special features) and connect it up to the external memory interface of another microcontroller. (hehe that's a trippy idea)

author: jaRON
author_rank: Contributor
timestamp: September 28, 2011, 07:36:04 am
content: what pin do you put microcontroller on if you like to code a microcontroller to respond to commands from another microcontroller

author: joelby
author_rank: Frequent Contributor
timestamp: September 28, 2011, 07:38:57 am
content: If you want two microcontrollers to communicate via SPI, I2C or UART, connect them together using their SPI, I2C or UART pins. If you want them to communicate via flags, connect an output pin on the first chip to an input on the second.Why don't you tell us exactly what you're hoping to achieve?

author: jaRON
author_rank: Contributor
timestamp: September 28, 2011, 07:52:09 am
content: I making a fan controller for my water cooling pc. I'm going to controll 15 to 17 fans. It going to have 8 Temperature Sensor and it 8 led bar graph. to show what the Temperature is. the fans are use a Irfz44 transistor so i going to need 94 to 100 pinand is there a better way to run the led bar graph. so i can save pins

author: IanB
author_rank: Super Contributor
timestamp: September 28, 2011, 07:59:58 am
content: If you need more outputs than the microcontroller has you should use an external shift register IC (or several).

author: joelby
author_rank: Frequent Contributor
timestamp: September 28, 2011, 08:02:25 am
content: I'm not sure how that relates to connecting multiple processors together. Either use a processor or FPGA with the required number of I/Os or consider multiplexing things. Temperature sensors with I2C interfaces can be multiplexed easily. You could even use I2C DC motor controllers. Or you can use shift registers or port expanders.

author: Psi
author_rank: Super Contributor
timestamp: September 28, 2011, 08:25:49 am
content: If you power the 8 segment led graph displays using an external IC connected to the analog voltage that the temp sensors produce you wont need lots of microcontroller outputs for all the leds.The LM3914 IC is a good example of this. It will drive a led graph displays and show the voltage level you supply it with by illuminate the leds as a bargraph.

author: PeterG
author_rank: Frequent Contributor
timestamp: September 28, 2011, 08:29:30 am
content: I would like to know where the 94-100 pin count comes from. He only needs about 36 io pins based on the description.8 for the 8 led display.8 for the 8 temp sensors if DS18b20 or similar are used.17 for the fan control outputs.Or did i miss read something.Regards

author: jaRON
author_rank: Contributor
timestamp: September 28, 2011, 08:32:55 am
content: Quote80 for the 8 of the 8 led display.8 for the 8 temp sensors6 for the fan control outputs.

author: PeterG
author_rank: Frequent Contributor
timestamp: September 28, 2011, 08:47:24 am
content: Could you multiplex the displays to reduce the number of pins required for the displays?Regards

author: Hypernova
author_rank: Unknown
timestamp: September 28, 2011, 01:02:51 pm
content: No way should you waste so much IO for the LED's, just use a chain of shift register and hook it up to the uC's SPI port.

author: jaRON
author_rank: Contributor
timestamp: September 28, 2011, 06:33:19 pm
content: is it easyer to use a lcd then the led bar graph

author: bruce273
author_rank: Contributor
timestamp: September 28, 2011, 06:40:57 pm
content: yes it's fairly common, ie all peripheral for computers will have micros in which just manipulate the data they recieve before it is sent to your pc. If you meant simulation as in a soft processor, You could simulate a micro controller on another one if your main micro is powerful enough tho an FPGA would be more suited to that job.

author: PeterG
author_rank: Frequent Contributor
timestamp: September 29, 2011, 12:10:28 am
content: jaRON, yes an LCD display would be easier and prob look better as well. Using an lcd also gives you more flexibility by allowing things like fan speed and actual temps to be shown.Regards