2 Feb Atmel’s AT91SAM7X/ is a member of a series of highly The AT91SAM7X and AT91SAM7X differ only in memory sizes. AT91SAM7XAU Microchip Technology / Atmel ARM Microcontrollers – MCU kB Flash 64kB SRAM 55MHz 4 PWM datasheet, inventory, & pricing. AT91SAM7X Microchip Technology / Atmel ARM Microcontrollers – MCU datasheet, inventory, & pricing.
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Welcome to the club. Therefor use extra transistors – they do inverting for you for proper PowerUp. But in the meantime I’ve noticed a very dissapointing detail about the controller.
AT91SAM | GPIO problem with AT91SAM7X
My problem is that I get a high impulse at power on of about 25ms, which is enough for the relais to switch. Protecting the IoT with Invisible Keys. Create free account Forgot password? I was going to ask what your drive configuration was.
BTW, the English is relays. Introduction to Microcontrollers Mike Silva.
ta91sam7x256 But then if you are running the relays at a higher voltage than the CPU, this won’t work either. Then the default state is for the transistor to be on and the internal pullup does not hurt.
That’s what inverters are for. Embedded Software Engineer Loft Orbital’s mission is to make space simple for organizations that need I’m used that GPIO come up with high impendancy and this behavour is really unexpected.
Of course if you want the default state to be off so it doesn’t drive the relays, at91aam7x256 you either need to use a pair of transistors or use a PNP transistor on the high side instead of an NPN on the low. Looks like your PA inputs can source as much as uA of current.
I don’t see any code piece in the startup code tampering with the GPIO. The only disadvantage of using the pull-down resistor to overdrive the pull-up is that you have to allow for the maximum pull-up current possible over temperature and process. On Thu, Aug 16, at I ended up using a hand full of Transistors to cover these issues properly.
Sign in Sign in Remember me Forgot username or password? I know that the ULN is designed for 5V pegel, but 3,3V gives enough current to safely drive my relais. This pulse is a flat 3,3V signal, no power up glitches or something. It seems that I need external pulldown to compensate them I didn’t find an errata in the Atmel datasheet.
GPIO problem with AT91SAM7X256
So a 1 kohm pull-down should do the trick. A very minor nit.
The pullups are enabled on reset and are possibly powerfull enough to supply enough current through the ULN It turns on both FETs and can create problems. Arduino Robotics Lonnie Honeycutt. Ah91sam7x256 cheap and compact.