jakobabs/design-challenge-jacob-kelly: NRF52840 evaluation board with a battery charger...

Chat

Welcome to Flux

Treat Flux like your intern. Tell it what you'd like to build and it'll get to work. You can also ask it questions, brainstorm ideas, and teach it your preferences. Learn More

Explain project

Write a project description

Find schematic issues

Create a test plan

Ready.

help me create the antenna for the nrf52840

jakobabs

@copilot help me create the antenna for the nrf52840

copilot

The nRF52840 is a versatile SoC from Nordic Semiconductor that includes a built-in RF transceiver supporting various wireless protocols. In designing the antenna for the nRF52840, you need to follow careful layout and design principles to ensure optimal RF performance.

Key Steps to Design the Antenna for the nRF52840:

Select the Antenna Type: The most common types for this frequency are PCB trace antennas like meandered or inverted-F antennas (IFA), chip antennas, or external antennas.
Place the Antenna Properly: Position the antenna at the edge of the PCB, away from noisy components.
Impedance Matching: Ensure the antenna is impedance-matched to 50 Ω to maximize power transfer and minimize reflection.
RF Layout Guidelines: Follow Nordic’s PCB layout guidelines for the RF section, such as grounding, shielding, and trace width.

Steps for a Meandered Inverted-F Antenna (MIFA)

Antenna Layout:
- Create a meandered line on the PCB with a length that achieves resonance at approximately 2.4 GHz.
- Start with a trace width of around 1 mm and a length adjusted to fit the space available.
Ground Plane:
- Ensure there is a continuous ground plane under the RF section, but keep it away from the antenna area itself.
Matching Network:
- Include a matching network with SMT components like capacitors and inductors to fine-tune the impedance. Use the network connected to the antenna feedpoint.
Testing and Tuning:
- Use a vector network analyzer to measure the impedance and adjust the matching network as necessary.

Sample Schematic Connections:

Connect the antenna to the nRF52840 as follows:

Antenna Feedpoint: Connect to $U1:ANT$ .
Matching Network: This typically includes components like an inductor (L1) and two capacitors (C16 and C17).

Example connections:

Connect $U1:ANT$ to matching network components.
Connect matching network output to the antenna feedpoint.

Example Layout:

Antenna Design:
- Start from the $U1:ANT$ pin and draw the antenna trace.
Ground Plane Clearance:
- Keep a clearance of around 2-3 mm around the antenna’s trace.

Adding Parts to Your Schematic:

You can use the built-in components in Flux:

Matching Network Components: Choose appropriate 0402 or 0603 capacitors and inductors.
PCB Antenna: Design the trace to match your antenna specifications directly on the PCB layout tool in Flux.

Example Values for a Matching Network:

$L1$ : 3.9 nH
$C16$ : 0.5 pF
$C17$ : 1.0 pF

Would you like to proceed with a specific antenna type, or do you need further details on the matching network components and layout? Let me know, and I can provide more tailored guidance!

Someone is typing...

Note: IC2 the PAT9130 trackball sensor from PixArt. Since the datasheet is confi...

jakobabs

Note: IC2 the PAT9130 trackball sensor from PixArt. Since the datasheet is confidential, the information shown here is in compliance with the NDA I signed. No further information regarding the PAT9130 will be given.

Someone is typing...

C5 -> W1 C6 -> AD23 C7 -> A22 C8 -> AD14 C9 -> B1

jakobabs

C5 -> W1 C6 -> AD23 C7 -> A22 C8 -> AD14 C9 -> B1

Someone is typing...

what capacitance should I use for this oscillator?

jakobabs

@copilot what capacitance should I use for this oscillator?

copilot

To determine the appropriate capacitance values for your oscillator circuit with the ABS07-32.768KHZ-T crystal, you typically need to refer to the crystal's datasheet. The common load capacitance for 32.768 kHz crystals is usually between 9 pF to 12.5 pF.

However, based on common practices, you might start with 12 pF for the capacitors ($C13$ and $C12$) if the specific datasheet is not available.

Here is a typical configuration to connect your oscillator:

Connections:

Connect $X1$:P1 to $U1$:XL1/P0.00.
Connect $X1$:P2 to $U1$:XL2/P0.01.
Connect $X1$:P1 to $C13$:P2.
Connect $X1$:P2 to $C12$:P2.
Connect $C13$:P1 to GND.
Connect $C12$:P1 to GND.

This should give you a stable 32.768 kHz oscillation for your NRF52840-QIAA-R microcontroller. If you have the specific datasheet for your crystal, I would recommend confirming the exact load capacitance values.

Someone is typing...

TFT_TC

TFT_CC

TFT_RT

GPIO5

TFT_BL

TFT_SI

GPIO5

PAT_5

TFT_TC

TFT_RT

TFT_SO

GPIO3

TFT_CC

GPIO2

PAT_9

TFT_SO

PAT_8

GPIO2

TFT_SI

TFT_CK

GPIO1

TFT_DC

TFT_BL

GPIO6

GPIO3

3V3

Resistance

3.3k Ω

PAT_7

GPIO4

TFT_CK

GPIO1

GPIO6

3V3

PAT_10

TFT_DC

C15

Capacitance

12p F

Reviews

Electrical Rule Checks

Missing Footprints

Reports parts that have no footprint.

Design Rule Checks

Overlapping Copper • 33

Des	Net	Des	Net
Trace 3c2c	GND	IC1:71687bae	None
Trace 3877	GND	U1:dc11b637	None
Trace 5780	GND	U1:dc11b637	None
Trace 6579	GND	U1:dc11b637	None
Trace ab11	GND	U1:dc11b637	None
Trace ae3b	GND	U1:dc11b637	None
Trace b570	GND	U1:dc11b637	None
U1:VSS	GND	U1:dc11b637	None
U1:VSS	GND	U1:dc11b637	None
U1:VSS	GND	U1:dc11b637	None
U1:VSS	GND	U1:dc11b637	None
Via	GND	U1:dc11b637	None
Via	GND	U1:dc11b637	None
Trace 1f00	Net 12	U1:P0.17	None
IC1:71687bae	None	IC1:VSS	GND
IC1:71687bae	None	IC1:VSS	GND
IC1:71687bae	None	IC1:VSS	GND
IC1:71687bae	None	IC1:VSS	GND
IC1:71687bae	None	Trace 9cf4	GND
IC1:71687bae	None	Trace 877e	GND
IC1:71687bae	None	Trace b3c7	GND
IC1:71687bae	None	Trace b95a	GND
IC1:71687bae	None	Trace b257	GND
IC1:71687bae	None	Trace c55f	GND
IC1:71687bae	None	Trace ff35	GND
IC1:71687bae	None	Via	GND
IC1:71687bae	None	Via	GND
IC1:71687bae	None	Via	GND
IC1:71687bae	None	Via	GND
U1:dc11b637	None	Trace f8c4	GND
U1:dc11b637	None	Via	GND
U1:dc11b637	None	Via	GND
U1:P0.17	None	Trace f20d	Net 12

Invalid Layer

Reports nodes that are assigned to a layer that doesn't exist in the layout stackup.

Component Overrides • 53

	Designator	Ruleset
	IC2:Pin_1	Override rule for Pin_1
	IC2:Pin_2	Override rule for Pin_2
	IC2:Pin_3	Override rule for Pin_3
	IC2:Pin_4	Override rule for Pin_4
	IC2:Pin_5	Override rule for Pin_5
	IC2:Pin_6	Override rule for Pin_6
	IC2:Pin_7	Override rule for Pin_7
	IC2:Pin_8	Override rule for Pin_8
	IC2:Pin_9	Override rule for Pin_9
	IC2:Pin_10	Override rule for Pin_10
	IC2:Pin_11	Override rule for Pin_11
	Rectangle Shape	Override rules for Rectangle Shape
	SJ1:P1	Override rules for P1
	SJ1:P2	Override rules for P2
	TP1:TP	Override rules for TP
	TP2:TP	Override rules for TP
	TP3:TP	Override rules for TP
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	＊｀REF｀＊	Override rule for ＊｀REF｀＊
	J＊＊	Override rule for J＊＊

Airwires • 4

	Designators	Net
	Trace 0be0:Trace 0be0, Trace efa7:Trace efa7	Net 1
	Trace 065e:Trace 065e, Trace 8826:Trace 8826	Net 1
	Trace 6103:Trace 6103, U1:VDD	Net 1
	U1:VDD, Trace 065e:Trace 065e	Net 1

Deprecated Rules

Reports nodes that are using rules that are not supported anymore.

Layers with Multiple Fills

Reports layers that have multiple copper fills of different nets. Make sure the Connected Layers rule value of nets with fills is valid.

Floating Copper • 1

	Name
	Trace 12fe

Protected Intrusions

Reports intrusions from objects of other nets into polygons or fills that have the Protected layout rule applied.

Manufacturing

Manufacturer Part Number • 36

	Designator	MPN
	C1	None
	C2	None
	C3	None
	C4	None
	C5	None
	C6	None
	C7	None
	C8	None
	C9	None
	C10	None
	C11	None
	C12	None
	C13	None
	C14	None
	C15	None
	C16	None
	C17	None
	C18	None
	C19	None
	C20	None
	C21	None
	C22	None
	C23	None
	C24	None
	C25	None
	IC2	None
	J3	None
	L1	None
	R1	None
	R2	None
	R3	None
	R4	None
	R5	None
	R6	None
	R7	None
	R8	None

Parts Available

Beta

Checks that all parts have a part number and are available from distributors.

System Checks

Auto-Layout

Beta

Reports issues with Auto-Layout if Flux cannot route something or must ignore a configuration.

Passive Components

Resistor Power Rating

Beta

Checks that the power traveling across a given resistor is under its rating with 50% headroom.

Learn more

Pull Up/Pull Down Presence

Beta

Checks that IC pins that require pull up or pull down resistors have them.

Learn more

Capacitor Voltage Rating

Beta

Checks that capacitors have appropriate voltage ratings to prevent overheating and ensure reliable circuit operation.

Ground
A common return path for electric current. Commonly known as ground.
jharwinbarrozo
20.5M
Net Portal
Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
jharwinbarrozo
43.0M
Power Net Portal
Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
jharwinbarrozo
11.4M
Generic Resistor
A generic fixed resistor for rapid developing circuit topology. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0Ω 10Ω 100Ω 1.0kΩ 10kΩ 100kΩ 1.0MΩ 1.1Ω 11Ω 110Ω 1.1kΩ 11kΩ 110kΩ 1.1MΩ 1.2Ω 12Ω 120Ω 1.2kΩ 12kΩ 120kΩ 1.2MΩ 1.3Ω 13Ω 130Ω 1.3kΩ 13kΩ 130kΩ 1.3MΩ 1.5Ω 15Ω 150Ω 1.5kΩ 15kΩ 150kΩ 1.5MΩ 1.6Ω 16Ω 160Ω 1.6kΩ 16kΩ 160kΩ 1.6MΩ 1.8Ω 18Ω 180Ω 1.8KΩ 18kΩ 180kΩ 1.8MΩ 2.0Ω 20Ω 200Ω 2.0kΩ 20kΩ 200kΩ 2.0MΩ 2.2Ω 22Ω 220Ω 2.2kΩ 22kΩ 220kΩ 2.2MΩ 2.4Ω 24Ω 240Ω 2.4kΩ 24kΩ 240kΩ 2.4MΩ 2.7Ω 27Ω 270Ω 2.7kΩ 27kΩ 270kΩ 2.7MΩ 3.0Ω 30Ω 300Ω 3.0KΩ 30KΩ 300KΩ 3.0MΩ 3.3Ω 33Ω 330Ω 3.3kΩ 33kΩ 330kΩ 3.3MΩ 3.6Ω 36Ω 360Ω 3.6kΩ 36kΩ 360kΩ 3.6MΩ 3.9Ω 39Ω 390Ω 3.9kΩ 39kΩ 390kΩ 3.9MΩ 4.3Ω 43Ω 430Ω 4.3kΩ 43KΩ 430KΩ 4.3MΩ 4.7Ω 47Ω 470Ω 4.7kΩ 47kΩ 470kΩ 4.7MΩ 5.1Ω 51Ω 510Ω 5.1kΩ 51kΩ 510kΩ 5.1MΩ 5.6Ω 56Ω 560Ω 5.6kΩ 56kΩ 560kΩ 5.6MΩ 6.2Ω 62Ω 620Ω 6.2kΩ 62KΩ 620KΩ 6.2MΩ 6.8Ω 68Ω 680Ω 6.8kΩ 68kΩ 680kΩ 6.8MΩ 7.5Ω 75Ω 750Ω 7.5kΩ 75kΩ 750kΩ 7.5MΩ 8.2Ω 82Ω 820Ω 8.2kΩ 82kΩ 820kΩ 8.2MΩ 9.1Ω 91Ω 910Ω 9.1kΩ 91kΩ 910kΩ 9.1MΩ #generics #CommonPartsLibrary
jharwinbarrozo
1.5M
Generic Capacitor
A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF 10pF 100pF 1000pF 0.01uF 0.1uF 1.0uF 10uF 100uF 1000uF 10,000uF 1.1pF 11pF 110pF 1100pF 1.2pF 12pF 120pF 1200pF 1.3pF 13pF 130pF 1300pF 1.5pF 15pF 150pF 1500pF 0.015uF 0.15uF 1.5uF 15uF 150uF 1500uF 1.6pF 16pF 160pF 1600pF 1.8pF 18pF 180pF 1800pF 2.0pF 20pF 200pF 2000pF 2.2pF 22pF 20pF 2200pF 0.022uF 0.22uF 2.2uF 22uF 220uF 2200uF 2.4pF 24pF 240pF 2400pF 2.7pF 27pF 270pF 2700pF 3.0pF 30pF 300pF 3000pF 3.3pF 33pF 330pF 3300pF 0.033uF 0.33uF 3.3uF 33uF 330uF 3300uF 3.6pF 36pF 360pF 3600pF 3.9pF 39pF 390pF 3900pF 4.3pF 43pF 430pF 4300pF 4.7pF 47pF 470pF 4700pF 0.047uF 0.47uF 4.7uF 47uF 470uF 4700uF 5.1pF 51pF 510pF 5100pF 5.6pF 56pF 560pF 5600pF 6.2pF 62pF 620pF 6200pF 6.8pF 68pF 680pF 6800pF 0.068uF 0.68uF 6.8uF 68uF 680uF 6800uF 7.5pF 75pF 750pF 7500pF 8.2pF 82pF 820pF 8200pF 9.1pF 91pF 910pF 9100pF #generics #CommonPartsLibrary
jharwinbarrozo
1.5M
Generic Inductor
A generic fixed inductor for rapid developing circuit topology. *You can now change the footprint and 3D model at the top level anytime you want. This is the power of #generics
jharwinbarrozo
15.1k
Terminal
An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
natarius
RMCF0805JT47K0
47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film #forLedBlink
jharwinbarrozo
1.2M
875105359001
10uF Capacitor Aluminum Polymer 20% 16V SMD 5x5.3mm #forLedBlink #commonpartslibrary #capacitor #aluminumpolymer #radialcan
jharwinbarrozo
1.2M
CTL1206FYW1T
Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric) #forLedBlink
jharwinbarrozo
1.1M

Inspect

Design Challenge - Jacob Kelly

Controls

Properties

Availability & Pricing

Distributor		Qty 1
	Arrow	$6.65–$30.84
	Digi-Key	$7.63–$33.66
	LCSC	$10.33–$29.31
	Mouser	$6.30–$135.63
	Verical	$7.17–$15.32

Assets

Thumbnail

render.png

id=render

Welcome 👋

Flux helps you build PCBs faster with an AI teammate!

Create your account to collaborate, stay updated, fork your own version, and get instant answers from our AI agent.