In my limited experience, PCBWay will do it, also Eurocircuits.
At Eurocircuits you set it all up in their UI, the option is under Advanced Options, “Via filling/Hole plugging” and you can even choose the type of filler (“Resin”).
At PCBWay you have to tell them using the notes or via your customer rep that you want vias filled. Normally they ask you when they see you have via-in-pad but didn’t specify.
Of course there is a small surcharge for this service
But the problem with 0.4mm pitch and via-in-pad is more the via size… how thick is your board? At normal 1.6mm thickness the smallest through hole via you should make is 0.35/0.1, assuming they’ll agree to drilling with 0.1mm (surcharge!). So that’s already too big for a pitch of 0.4mm…
Micro vias can be 0.1mm drill, but that leaves 0.1mm spacing using a annular ring of 0.1
The question is, if they can hit the pad with a micro via… Maybe the filling is insignificant when the micro_via is plated. I think that is the trick. There should be enough solder paste to fill the void
They certainly can! PCBWay prefers to drill micro-vias, but I think they can also laser them.
But micro-vias are subject to constraints - in particular they go from one layer to the next, you can’t choose any layer as the target, and I think with the lasers they can only do fairly thin depths so on a 4 layer design you can use them from layer 1 to layer 2.
And they will totally change the cost of the board - the cheap prototype prices depend on your board matching the parameters of everyone else’s designs. All those designs get combined together onto the big PCB panels they produce and undergo the same process - this way you get cheap prices.
If your design has micro-vias it has a different process than the cheap PCBs. The micro-vias get lasered or drilled onto the layer 1/2 panel before it gets glued to the layer 3/4 panel. It will be scheduled with other “advanced” PCB designs, or worse, given its own panel… the price will be very much higher than the normal “$5 for 10 boards” type deals. More like $600 for 10.
Hey but looking at the picture, it looks like you can fit traces between those pads…
PCBWay will do 0.1mm traces for only a small surcharge, it will be much cheaper than using micro-vias…
And then you could do a ground plane in layer 2, and signals in layers 1 & 3, a much better stackup IMHO.
Looking at how nordic is doing it in the hardware design folder. It uses microvias. In order to utilize the full potential of this Dual Core MCU, it is unfortunately, necessary to drill microvias. That kind of clearance (0.035mm) is not realistic.
From what I understand its a cost issue due to filling and small drills, but as long as they’re filled they should be fine… so if the cost isn’t an issue then go right ahead!
it’s unfilled vias in pads that can cause problems as the solder will leak out through them.
But I would advise choosing a fab and talking to them (or checking their online specs) in advance to find out what they can do. It’s a real pain to have to redo all the vias once a design is already done.
Do someone know, if there is a morse-code equivalent code for RGBW signaling?
The 4 buttons could be red, green, blue, white. White for stop bit. The device could then translate the color signaling. Maybe the phone camera can pick up the signals. There should be a protocol for initializing and synchronizing clock.
According to the datasheet, the nrf5340 can execute code directly on the external FLASH through QSPI.
Using the internal DC/DC regulator we can have the pins HIGH @1.8v (Default) and therefore level_shifters for the ICM-20948 is not needed. Apparently the ICM-20948 can communicate with a 3. Party I2C sensor, via high speed SPI interface to the nordic IC
Communication between the application core and the network core happens through a shared memory area. The application core memory is mapped to the network core memory map. This means that the network core can access and use the application core memory for shared memory communication.
Interprocessor Communication (IPC) is used to indicate to the other core that there is new data available to pick up. The actual data exchange is handled by Open Asymmetric Multi-Processing (OpenAMP).
Zephyr includes the OpenAMP library, which provides a complete solution for exchanging messages between the cores. The IPC peripheral is presented to Zephyr as an Interprocessor Mailbox (IPM) device. The OpenAMP library uses the IPM SHIM layer, which in turn uses the IPC driver in nrfx.
Because the screen is 3.3v logic only, while the driver can work with1.8v, I have laid my eyes on another screen using QSPI. Since the external FLASH is on the QSPI port, i’m not entirely sure how loading stuff from FLASH to screen will happen, but i guess there should be a buffer involved. The screen is 360 x 360 circular LCD @1.32inches, so a noticeable improvement in pixel density. Since it´s a QSPI interface screen, it is very fast, like instant refresh fast. I feel more comfortable going with that screen, since it is a good candidate to pair with the Nordic nRF5340.
Do you think 6-axis motion will suffice, for e-bike and VR controller ? Is the compass really needed, especially if the e-bike application can pair with smartphone via BLE. Having the gyro and acceleration data will obviously be needed for motion plotting to motor controller. When we pedal the bike, the bike frame will shift slightly from side to side. This movement can be directly translated to cadance. Furthermore, how much the bike swings from side to side, can tell us something about how much force the rider is putting into the pedals. Not as a linier function, but pulling the handlebar, when pedaling hard to gain acceleration, the motor controller can put in some more watt´s, and thereby making the rider feel bionic.
Does someone have experience driving several slaves on a QSPI bus? Can we use a general IO pin for Chip Select (CS)? [Edtit] (I believe the nCS - QSPI pin described in the nordic doc´s is for QSPI flash integration, so driving a secund slave on those datalines, just requires a second CS pin for that other QSPI device (Screen))
[USE CASE]
Let´s say the device is connected to your phone via Bluetooth. The phone is in your backpack or maybe your pocket. Still you can stream maps and directions to your handlebar. Having the phone connectivity and huge processing power at hand. If you wear a heart rate tracker, you could have those data on display as well.
Either the screen will have to be raised a bit on some double sided tape or the pins on the screen side will have to be sanded/filed down. Maybe both. [Edit] or I move the FET´s to the 2nd layer and just route the signals, making room for SMD 1.27mm header_pins
