Showing posts from January, 2005

Moving code from ESP8266 to ESP32

A while ago I made a mashup of Dan Royer's code CNC 2 Axis Demo with my own code for trapezoidal motion stepper and servo control for ESP8266.

I assumed porting the code to the ESP32 would be trivial, and that was true for the most part: changes like library name being Wifi.h instead of Wifi8266.h were not a problem. UDP now does not like multicharacter writes but you can use print instead. So far so good.

However, when it came to the interrupt code I was stuck with the stepper interrupt causing an exception sometimes. And to make things weirder, the servo interrupt worked flawlessly (both of them had the IRAM_ATTR directive if you ask me).

Going little by little, I could narrow down the culprit to a floating point operation during the interrupt, that would cause problems sometimes but not always. Browsing around I found this post. Where the solution was simple: do not use floats within the interrupt routines but doubles. The reason was the float calculation would be performed by…

New wireless router

After five years of trouble-free operation with my 11Mbps D-link DWL1000-AP 802.11b wireless access point I decided to upgrade my home wireless gear. The USRobotics USR-8000A router with print server and the access point were replaced by an SMC2804WBRP-G that contains a print server (for USB printers), 54Mbps 802.11g wireless access point, four ports FastEthernet switch and router, all in one nice box.

My initial research on the net told me the product firmware was quite poor, with lots of users reporting different problems. However, because the retail price was under 100 Euros I decided to give it a try.

The results: I configured the router off-line and then I just switched the old by the new gear on the fly. The p2p software I was running on a server continued running as happy as before. I was a bit dissapointed as the unit's current firmware does not provide fixed IP mapping, this can be a problem.

After some hours of happy networking my son complained an streamed show he was …

A nice video projector

These holidays we've got some new stuff to play with. I'm very impressed with the new Creative Zen Micro, which is a harddisk based 5GB MP3 player plus FM radio plus voice recorder. It looks cool, it sounds superb and the software just works. Very nice too is the new Muvo (same capabilities but Flash-memory based, ours is only 256 MB).

But the star has been the PB1600 video projector. It really delivers a great image for either DVD or VGA. It's 800x600 DLP-based but our 1024x768 iBook displays just fine. Now I need to get a projection screen to get the best result.