From 29f7e10ba6050a2cfb921f98dbacea08781ba9cc Mon Sep 17 00:00:00 2001 From: davor Date: Sun, 27 May 2018 10:20:06 +0200 Subject: [PATCH] readme update --- README.md | 41 ++++++++++++++++++++++++++++++----------- 1 file changed, 30 insertions(+), 11 deletions(-) diff --git a/README.md b/README.md index e38dd08..54f5c65 100644 --- a/README.md +++ b/README.md @@ -49,16 +49,6 @@ run its games, but can do much more. kicad ulx3s.pro -[PCB v1.7](/pic/ulx3st-real.jpg) is produced. For this board to work, -IPC CLASS 3 quality PCB is required, 5/5 mil resolution and 0.2 mm holes. -Important board features are tested and work like -USB-JTAG, SDRAM, SDCARD, HDMI, FLASH, RTC, I2C, OLED, AUDIO, ADC, 433.92MHz -US2 can be used to plug USB-PS/2 combo keyboard but US2 feature as USB -host/device is not tested. -There are known issues, luckily most can be fixed by -[Upgrading PCB v1.7](/doc/pcb-v1.7-upgrade.md). - - # Features FPGA: Lattice ECP5 LFE5U-85F-6BG381C @@ -93,12 +83,41 @@ Clock: 25 MHz onboard, external differential clock input Low power sleep: RTC clock wakeup, power button, 32768 Hz quartz and battery - GPDI is General Purpose Differential Interface, Electrically LVDS, mostly TMDS tolerant female receptacle more-or-less compatible with digital monitors/TVs +# Production + +If you are going to order this project by yourself, it is important +what manufacturer to choose for PCBA (PCB and Assembly) service. + +Choose PCBA manufacturer which can produce PCB of IPC CLASS 3 quality, +5/5 mil trace resolution and 0.2 mm holes. +Avoid manufacturer who claims "quality" and "satisfaction" but doesn't +really know what will be IPC CLASS rating for this project. + +PCBA manufacturer prices for the parts should be approximately equal as those +from distributors like [Mouser](www.mouser.com) or [DigiKey](www.digikey.com). +Avoid any PCBA manufacturer who asks 3$ for the 1$ part or 40$ for the 30$ part. +Select [Mouser](www.mouser.com) language/location icon to PCBA manufacturer +country of origin and $-currency to check is PCBA manufacturer telling the truth +about prices. + +[PCBWAY](www.pcbway.com) produced [ULX3S v1.7 45F](/pic/ulx3sb-v17.jpg) in +December 2017 at above of CLASS 3 quality, $126 per board. +[PCBWAY](www.pcbway.com) produced [ULX3S v1.8 85F](/pic/ulx3sb-v18.jpg) in +May 2018 at the edge of CLASS 1 quality acceptance +(drill randomness and copper layer misaligment, hole breakout about 180°), +$134 per board. +[PCBWAY](www.pcbway.com) is cheap at boards and assembly but asks +$40 for FPGA 85F chip which costs $30 at [Mouser](www.mouser.com). + +[PCBCART](www.pcbcart.com) would be my next choice because they +offer CLASS 3 quality and assembly at reasonable cost. Prices for the +parts are equal as from [Mouser](www.mouser.com) so total price per +board should be about the same as above. # Todo