C6/C7/L1/U2 are the DCDC.
For the LDO, you should have C8, C9, R4 and U3.
Q3 is reverse voltage protection for VIN (not used if you use USB).
C5 is no-stuffed and I can’t even find a C10 in the schematic 
Cool. I think I am good to go. C10 is adjacent to C1. Thanks! Using the LDO does not increase the current available at each pin, correct? Just more current available for modules?
An LDO is just less efficient at taking VIN and making it 3.3v; it doesn’t change the imp’s operation at all.
@Hugo I believe you mentioned that you don’t use stencils in house. Do you use a syringe for paste? The boards I ordered are ENIG, so I am trying to figure out the best thing to use for either reflow in a toaster oven and hand soldering. Any suggestions?
We just use 22awg solder - no paste at all. For the amber you should be able to hand solder everything. We don’t have a reflow oven, so everything apart from DFNs and BGAs are just done with a hand soldering iron.
DFNs/BGAs are done by getting some solder on the pads with a hand iron, drenching in in flux and then preheating/hot air to reflow the joints.
This is far by the quickest/easiest method but does take some practice
Got it. I assume you get ENIG boards as well then? Any preference on leaded or lead-free solder, environmental issues aside?
FYI for anyone looking, Radio Shack is getting ready for Christmas and has a lot of things on clearance. I picked up a lamp/magnifying glass/articulating arm station for 62% off. Its no microscope, but it helps.
Our boards tend to be HASL because they’re just the cheapest option from gold phoenix
Got my Amber boards from SeeedStudio. This is my first run, but I’m pretty pleased. Hand-soldered all the components and got it blinked up.
@Hugo I do have a question about the LED. I ended up sliding the LED all the way to the edge of the pad to avoid soldering the two cathodes together on the end of the component. Is there a better way to do this?
Can I just say… Holy Crap those capacitors are tiny.
Very pretty in black! Generally, lots of flux and not too much solder is the only way to prevent close things from shorting…
Guess so… I moved the LED back into the center of the pad and carefully soldered only the left edge. Looks like it worked. I still don’t understand why they would put both cathodes on the same side of the component… I’m sure that there is a reason.
Got a few extra? Without the imp on it? I’m interested!!
Yep. I only got 10, but I’d be happy to sell a few and make another run. I have all the components and boards. I’ll PM you.
Sweet! Definitely interested in assembling some of these.
Are you interested in boards, components and imps, unassembled? I just need to sort out a way of packaging everything up so it is easy to ship and use. Most of the stuff is cut-reel. I’ve built two so far, and its not terribly difficult, with the exception of the SMT LED… where both cathodes sit over the same pad. Let me know what you are interested in. Thanks!
Edit - Sorry - I thought I PMed this. If anyone else is interested in the Amber boards, please PM me, then we don’t have to keep hitting this thread.
That looks great!
I’ve got a question about the Amber reference design. The board is laid out to populate with either SMT or TH parts for the blink-up circuit, and both parts are in the BOM. However, the SMT LEDs are Common Anode, and the TH LEDs are Common Cathode. I realized this last night after switching an Amber board from SMT to TH and getting incorrect color codes. Am I missing something or is the TH part on the BOM incorrect?
The module will support both. Not sure if the amber reference design has been updated, but the resistor across the red LED (used for polarity detect) should be 10k not 100k.
FYI: the IMP002 module spec sheet (version 20130710) in the Developer Wiki still mentions 100k !
R2 & R3 are both listed as 100 Ohm in the BOM, and that is what I have them populated with. I think I am confused.
R4 is the phototransistor bias resistor, and 100K is correct for that.