Best posts made by ccs hello

Normally 0V, When pressed, about 2.1v as logic high.

FW_RST is a software based Reset driven by the Omega2 base code.
RST, afaik, is a hardware reset (or halt.) My (previously) defect board had this pin tied to Gnd, which halted the board (only consumed 20 mA, and as cold as dead.)
3.3V_out, is also known as NET_Power. The term is carried over from the original Omega (Omega 1.)
Currently (at least in few boards I know of), they are kept as float (not connected.)**

Original Omega1's NET_Power supplies 2V to AR9331's Ethernet MAC transformer's C.T. (center tap) as the chip's DC bias.
It appears that MT7688 does not need external DC bias for Ethernet MAC, thus this pin is left open.
I.e., there is no 3.3v output at this pin.

** There are two unpopulated zero-ohm resistor positions on the PCB for shunt. One of them, if short-circuited, appears to be able to supply 3v3.

ccs_hello

re: LiFePO4 or Li-Ion rechargable battery technology

It's always advisable to add bettery charge/discharge protection circuitry, instead of just cell only.
With that in mind, the commonly seen Li-Ion 3.7-4.2v Li-Ion is more attractive, just add a buck (step-down) converter to drop the battery voltage to 3.3v. Most of the design works when cell drops in between 3.3 - 3.0v (output voltage = input.) When cell drops below 3.0v, protection circuit cuts out to protect the battery.

A TP4056 based charger/1 cell protection based combo serves as the first part of the design, then add a 1A or 2A step down to complete the design.

ccs_hello

I think it will also be good to show the soldering defect cases:

Case 1 (mine), see picture

https://community.onion.io/topic/1159/omega2-almost-doa/

Case 2 (picture in the link)
https://community.onion.io/topic/1159/omega2-almost-doa/5

Case 3 (picture in the link)
https://community.onion.io/topic/1327/omega-2-doa/10

ccs_hello

I'd like to share on what I learned on my Omega 2 Plus unit. When I received the board, I noticed there are a few solder balls and splatters on the PCB or near the 2mm pitch connector pins. I immediately rubbed them and took them off. Then I tried to power it up but the amber LED never lit nor blinking at all. If I used a lab bench power supply with 3.3V direct-powering, the current consumption is just 20mA and the metal RF shield never gets warm. I also used a min-dock with microUSB powering. USB power meter showed current consumption increased for about 20mA (at 5V), also no amber light nor warming up. After struggling for awhile and checking on published data, I became suspect the Omega2+'s pin 16 (lower left corner) Reset_B (or RESET) is grounded to the PCB trace that is grounded thru a solder splatter. It really looked like a circuit trace. I used a Xacto knife to take it out and now it is working normally (consuming 3.3V 170mA, getting warm, and amber LED blinking then stable.) BTW I found out that in my PCB, pin 25 Net_POW (right side, the 8th pins counting down) is not connected to anything as oppose to 3.3V power output shown in the PINOUT Diagram. Actually on PCB, there are two reserved zero-ohm resistor positions, none populated. One is for 3.3V out and the other some type of logic IO. Hope this info is useful for some and possibly save an RMA.

@Yvan-Gagnon
Proper powering is absolutely essential for Omega2 series.
That extra drain from webcam certainly would make it even harder.
In the forum there are many discussions about power arrangement and a few commonly made mistakes. Please take a look at them.
Also sharing exactly what you've used (the power supply, cabling, connectors, etc. would certainly help.

Yes, very helpful.
There is THE official Dallas-semi's One-Wire (as a noun and very specific, 1-Wire) protocol, there is the almost-there, one-wire (as an adjective) protocol used by DHT11/22/AM2302.

See:
https://lastminuteengineers.com/dht11-dht22-arduino-tutorial/
and scroll down to the section with the heading:
"How DHT11 and DHT22/AM2302 Works?"

@ Valeri V
Hard to troubleshoot the power situation unless every single bit of info is known.
In addition to static voltage measurement, transient power dip in the milli-second level will cause O2 to hang.
Gold rule for power hygiene:

1. don't use long cable, or at least, use thick cable
2. put a large capacitor as close to the O2 side as possible (I used 470uF 6.3V low ESR capacitor)
3. proper use of power regulator IC
   Some commonly seen mistakes are
   a) use a clone/off-brand/sub-standard IC or that IC has already degraded (due to various conditions)
   b) not using the datasheet specified capacitors on its input and output side
   < --- many cheap suppliers do that to save its cost
   < --- they need to be as close to the IC as possible
   c) no or insufficient heat sink and/or heat dissipation (will degrade the IC anyways)
   d) use the wrong part (e.g., mis-calculation on drop-out voltage)
4. Use improper connection such as DuPont connector and header pins

All of them are basic EE knowledge and are essential for a success project
but some DIY maker Wikis/books failed to mention.

Insufficient power supply.

LEDE, OpenWRT, etc.
Embedded Linux, designed for resource limited hardware.

NO. Not possible.

Nice work!
Can we run some number just to validate my understanding is correct...

If it's 320x240 ( @ 16 bit/pixel) per image frame
and such individual (different) frames are transfer 80 times per second, thus
320x240x16x80 = 98.304 Megabits per second, not considering SPI overhead (and I am thinking the SPI protocol engine is hardware based fetching directly from RAM space.)

Later post stated 12 fps, which will be
320x240x16x12 = 14.8 MHz pixel clock (not padded with SPI and frame fetching overhead), while SPI is clocked at 48MHz.
<-- here I am assuming MT7688 SoC is doing something else (such as running other code, e.g., build new frames, housekeeping, application code, etc.)

In my view, the usability would be how much of the CPU time is left over for Omega2+ to perform its regular job (other than screen refreshing)? Do you have a guesstimate?

ccshello

Wrong choice on that AMS1117 based power supply, especially if you get it from Ali or fleaBay. They lack the output BIG capacitor and/or the output wiring/connector to Omega2+ is insufficient.

I'd suspect its the power supply problem, either the weak/no-good USB power source or lousy USB cable, or both.

LF33CV (3.3V LDO linear reg) regulator's output needs to direct-connect to your Omega2+ without going through the breadboard and must use a thick pair of wires (I recommend 20 AWG), soldered, not using connector-socket arrangement.
Also, put a separate 500uF/6V capacitor very close to Omega2's power input lead will be able to solve the power-dip problem during WiFi power-on stage during the boot-up and help stability.

Yes, Omega2 is very picky on its power supply.

On power dock's power input side, it appears not using USB's D+ and D- signaling leads. It should force the supply side to be 5V supply.
ACT2801's max input voltage is 6.5V and at 6V, it will trigger an input over-voltage protection, until the issue is resolved.

Battery Mgmt/Power Path IC ACT2801 (per Onion sch) uses Riost = 75K (which maps to 1A output current limiting), while standard design, per datasheet, is 100K (which maps to 1.5A.)

Consequence is that "no load auto-shutdown" is changed to 53.3mA nominal (worst case 133mA), from the standard design of 40mA (no load detection -- nominal) and 100mA (worst case.)
So in theory, when Omega2 is running in reduced power mode (WiFi off, no other peripherals) and current consumption is less than 133mA, there is a possibility the power control IC may think there is no load attached and set output to power-cutoff mode (until the load resumes to be high enough, by then it's too late.)

P.S. Datasheet only showed one sampling point (V batt supply = 3.7V) for above. Other situations one has to experiment.

Do not skip essential components specified by the IC datasheet.
It needs a 0.1uF input capacitor (for stability) and
one output capacitor (minimum of 10 uF.)
They have to be as closed to the IC as possible.

You have a power supply problem. The LD1117S33 (if authentic) needs minimum of input 0.1uF and output 10uF capacitors.
My recommended spec is input 47uF and output 470uF to handle power inrush demand by Omega2's sudden WiFi power on in around 19-20 seconds into the boot.
Also, do not use thin power supply wires. I recommend minimum of 22 Ga.

ccs_hello

@alihan-dikel

Note that this thread is about Omega, not Omega 2.
Omega 2 is rather picky, consumes more power, and has the habit of demanding high instantaneous current at times when voltage cannot drop below a lower voltage threshold known as brown-out Vcc.