Title: Ethernet LED driver - PCB Build
Post by: arhi on July 30, 2011, 11:19:45 pm
Post by: arhi on July 30, 2011, 11:19:45 pm
Ian kindly sent me Ethernet LED driver PCB. It is a stalled/abandoned DP project but since I never had a chance to try to embed ethernet into my projects it is a good starting point.
I had few issues with it. First, I hate soldering Al electrolytes in SMD version. They have no pins, they do not like heat so I can't use my heat gun and I do not have a soldering plate/oven and controlling anything on your kitchen glass plate ain't fun at all .. so initially I soldered the nasty buggers but I could not say with certainty they are on so I removed them and replaced them all with tantalum ones. Then I found out that 3 out of 4 were actually with footprint for tantalum one and only one had a can footprint... anyhow just gave me excuse to order a batch of SMD_A tantalum 10uF caps that I did not have in the drawer :)
Second issue I had was with the smd switch. I was unable to find locally (and I failed locating one at Farnell - probably was not looking hard enough) so I decided to use another SMD switch I ordinary use in my own projects (http://http://www.comet.bg/shop/datasheet1.html?ID=24680) that is 2 pins only but I placed it diagonally so it fits ok. (I still can't believe I was unable to find smd version of normal micro switch with 4 pins).
Third issue was with the Ethernet connector. I never used these so my exp is still noob. I noticed significant price differences in connectors. Noticed that there is 2 major versions - with some "coils" and without. Those without are seriously cheaper then one with so I assumed I need one with coils. Then among ones with coils there are ones with leds and without ... The connector I managed to find in Farnell (locally I only had ones without coils and without leds) is 113-7983 (http://http://uk.farnell.com/stewart-connector/si-60062-f/icm-1-1-full-magnetics-led/dp/1137983?Ntt=113-7983). Looks identical to what this board needs. Now the "problematic" part; other then sucker costing a lot for a connector (over 6eur when it gets here) the footprint was not 100% same :( .. led's are 0.5-1mm closer to the other pins then on the footprint so there's some nasty tension to place to connector and the led leads are now under angle but connector is on board and should work properly :)
Final problem was the power connector. This one destroyed me .. the hours searching lead me to this baby on Farnell (http://http://uk.farnell.com/multicomp/mj-179smt/chassis-socket-psu-smt-2mm-pin/dp/1737262?Ntt=173-7262) that looked like perfect match. When I wanted to mount it on board I noticed that center wire goes to ground and that outside of the connector goes to Vcc. As I hate having connectors wired that way (as all other connectors I have are center live and outside gnd) and there's no room for a gretz on board I had to do some nasty cutting so I cut the pads on the pcb and rewired the pcb so connector is "properly" connected.
The i2c pwm drivers are not soldered on as attm I do not plan to use them (I have only one anyhow) as I first need to get board to talk to ethernet first. I believe I'll go with UDP first as it should be simplest to implement, and try to send data to i2c (there will be bus pirate there waiting for data)... when I make something out of it, I'll create a new post in the "project log" section :) for now just few pics of the "assembled" board.
I had few issues with it. First, I hate soldering Al electrolytes in SMD version. They have no pins, they do not like heat so I can't use my heat gun and I do not have a soldering plate/oven and controlling anything on your kitchen glass plate ain't fun at all .. so initially I soldered the nasty buggers but I could not say with certainty they are on so I removed them and replaced them all with tantalum ones. Then I found out that 3 out of 4 were actually with footprint for tantalum one and only one had a can footprint... anyhow just gave me excuse to order a batch of SMD_A tantalum 10uF caps that I did not have in the drawer :)
Second issue I had was with the smd switch. I was unable to find locally (and I failed locating one at Farnell - probably was not looking hard enough) so I decided to use another SMD switch I ordinary use in my own projects (http://http://www.comet.bg/shop/datasheet1.html?ID=24680) that is 2 pins only but I placed it diagonally so it fits ok. (I still can't believe I was unable to find smd version of normal micro switch with 4 pins).
Third issue was with the Ethernet connector. I never used these so my exp is still noob. I noticed significant price differences in connectors. Noticed that there is 2 major versions - with some "coils" and without. Those without are seriously cheaper then one with so I assumed I need one with coils. Then among ones with coils there are ones with leds and without ... The connector I managed to find in Farnell (locally I only had ones without coils and without leds) is 113-7983 (http://http://uk.farnell.com/stewart-connector/si-60062-f/icm-1-1-full-magnetics-led/dp/1137983?Ntt=113-7983). Looks identical to what this board needs. Now the "problematic" part; other then sucker costing a lot for a connector (over 6eur when it gets here) the footprint was not 100% same :( .. led's are 0.5-1mm closer to the other pins then on the footprint so there's some nasty tension to place to connector and the led leads are now under angle but connector is on board and should work properly :)
Final problem was the power connector. This one destroyed me .. the hours searching lead me to this baby on Farnell (http://http://uk.farnell.com/multicomp/mj-179smt/chassis-socket-psu-smt-2mm-pin/dp/1737262?Ntt=173-7262) that looked like perfect match. When I wanted to mount it on board I noticed that center wire goes to ground and that outside of the connector goes to Vcc. As I hate having connectors wired that way (as all other connectors I have are center live and outside gnd) and there's no room for a gretz on board I had to do some nasty cutting so I cut the pads on the pcb and rewired the pcb so connector is "properly" connected.
The i2c pwm drivers are not soldered on as attm I do not plan to use them (I have only one anyhow) as I first need to get board to talk to ethernet first. I believe I'll go with UDP first as it should be simplest to implement, and try to send data to i2c (there will be bus pirate there waiting for data)... when I make something out of it, I'll create a new post in the "project log" section :) for now just few pics of the "assembled" board.
Title: Re: Ethernet LED driver - PCB Build
Post by: Nexus on July 31, 2011, 04:48:44 am
Post by: Nexus on July 31, 2011, 04:48:44 am
For anyone building DP ethernet boards, you can find the HanRun jacks on ebay (http://http://cgi.ebay.com/HanRun-105A-RJ45-Connector-10-100-Base-TX-Magnetics-LED-/150598361236?pt=LH_DefaultDomain_0&hash=item23105ca094).
Title: Re: Ethernet LED driver - PCB Build
Post by: arhi on July 31, 2011, 10:17:21 am
Post by: arhi on July 31, 2011, 10:17:21 am
Do you maybe know a non-ebay link for those? I'm not big fan of ebay purchases (non stop something don't work, I spent 3-4 days paying stuff, history dissapears etc etc etc .) so a regular online store would be preferable :)
Title: Re: Ethernet LED driver - PCB Build
Post by: ian on August 01, 2011, 11:41:40 am
Post by: ian on August 01, 2011, 11:41:40 am
Nice to see this one come to life. Please let me know if you need any help setting up the stack or pins, I've made several iterations of this (based on hack a day business card web server chipset).
Do you plan to use the microchip stack, or try FreeRTOS/etc?
Do you plan to use the microchip stack, or try FreeRTOS/etc?
Title: Re: Ethernet LED driver - PCB Build
Post by: arhi on August 01, 2011, 09:50:29 pm
Post by: arhi on August 01, 2011, 09:50:29 pm
I plan to try everything I let my hands on :D so if you have some links to some examples do not hesitate to share them :D
Title: Re: Ethernet LED driver - PCB Build
Post by: ian on August 01, 2011, 10:02:55 pm
Post by: ian on August 01, 2011, 10:02:55 pm
I feel you know more than I can ever hope to in a full lifetime, but here is a intro tutorial if you need a crash course on PPS and other PIC-stuff.
http://dangerousprototypes.com/docs/Int ... rogramming (http://dangerousprototypes.com/docs/Introduction_to_dsPIC33_programming)
I am also available to help if it is mid-night and you are banging head on table wondering why it doesn't work. Maybe I can give insight into a register or other dumb PIC thing that you missed that I also struggled with before. Probably not, but I am here if I can help ;)
http://dangerousprototypes.com/docs/Int ... rogramming (http://dangerousprototypes.com/docs/Introduction_to_dsPIC33_programming)
I am also available to help if it is mid-night and you are banging head on table wondering why it doesn't work. Maybe I can give insight into a register or other dumb PIC thing that you missed that I also struggled with before. Probably not, but I am here if I can help ;)
Title: Re: Ethernet LED driver - PCB Build
Post by: arhi on August 01, 2011, 10:41:50 pm
Post by: arhi on August 01, 2011, 10:41:50 pm
I meant links on some examples of ethernet use (rtos+eth etc), pic per se is simple device I am pretty acquainted with :D
Title: Re: Ethernet LED driver - PCB Build
Post by: ian on August 05, 2011, 01:33:49 pm
Post by: ian on August 05, 2011, 01:33:49 pm
Unfortunately, I think the only RTOS docs are the posts in the forum :( There are two nice ports with lots of work done, but no summary or description anywhere. I would really like to work with them myself, but have not found the chance (always easier to build on old MC stack projects).