SD card works a bit!
SD card works a bit!
A brief update on the build process and early bring up phase: I took some time on Sunday to build one board. The process was somewhat different than I thought, the things I anticipated to be tough (soldering by hand the ICs) were not while others turned out to take time (the bloody 100nF filter caps like to fly all over the place - better to hold breath when picking them up). For some reason the similarly sized resistors were easy to work with. I lost a few LEDs, simply by dropping them from my pliers from a height of about an inch over to the desk - they just disappeared
The pads of the 50MHz crystal oscillator are just under the device, so getting that one soldered was difficult, but I did manage to do that by applying solder on the pads first and then trying to heat them from the side. But I did get all the components in there before running out of time (build time 3h according to me and over 4h according to my wife...). I think the next one will take about two hours as I start to know what to do.
I attach a picture of the first application of power - amazingly the USB interface worked straight out the bat! I was able to get to the built-in boot loader where the ARM presented itself as a tiny USB flash device. So that proved already many components. I've also checked that the 50MHz oscillator does work and I've been able to load a design on the Xilinx chip to flash a LED from a 24 bit counter, and I can programmatically turn on and off a led from the ARM. Not all the LEDs work though, so there is hardware debugging to be done, but it is a good start given that after the build I have had only about an hour to work on this.
But it is very exciting, bringing things up to life is just a very rewarding experience!
Erik
SD card works a bit!
A brief update on the build process and early bring up phase: I took some time on Sunday to build one board. The process was somewhat different than I thought, the things I anticipated to be tough (soldering by hand the ICs) were not while others turned out to take time (the bloody 100nF filter caps like to fly all over the place - better to hold breath when picking them up). For some reason the similarly sized resistors were easy to work with. I lost a few LEDs, simply by dropping them from my pliers from a height of about an inch over to the desk - they just disappeared
The pads of the 50MHz crystal oscillator are just under the device, so getting that one soldered was difficult, but I did manage to do that by applying solder on the pads first and then trying to heat them from the side. But I did get all the components in there before running out of time (build time 3h according to me and over 4h according to my wife...). I think the next one will take about two hours as I start to know what to do.
I attach a picture of the first application of power - amazingly the USB interface worked straight out the bat! I was able to get to the built-in boot loader where the ARM presented itself as a tiny USB flash device. So that proved already many components. I've also checked that the 50MHz oscillator does work and I've been able to load a design on the Xilinx chip to flash a LED from a 24 bit counter, and I can programmatically turn on and off a led from the ARM. Not all the LEDs work though, so there is hardware debugging to be done, but it is a good start given that after the build I have had only about an hour to work on this.
But it is very exciting, bringing things up to life is just a very rewarding experience!
Erik