Bill of Materials

Thought for 1 min 18 sec

Generated BOM below with U2, A RS485 B, J1, and J2 excluded / DNP.

Pricing basis: lowest available unit price shown in Flux BOM distributor data. Items with no distributor pricing are marked N/A and excluded from the known-priced subtotal.

Capacitors

Table

Designator(s)	Qty	Value	Package	MPN	Manufacturer	Description	Est. Unit	Ext.
C1, C2, C6, C10, C11, C12	6	0.1 µF	0603	Not specified	Not specified	Ceramic capacitor	N/A	N/A
C3, C4, C8	3	10 µF	0603	Not specified	Not specified	Ceramic capacitor	N/A	N/A
C5, C9	2	10 µF	0805	Not specified	Not specified	Ceramic capacitor	N/A	N/A

Resistors

Table

Designator(s)	Qty	Value	Package	MPN	Manufacturer	Description	Est. Unit	Ext.
R1, R8, R9	3	10 kΩ	0603	Not specified	Not specified	Chip resistor	N/A	N/A
R2, R3	2	5.1 kΩ	0603	Not specified	Not specified	USB-C CC resistor	N/A	N/A
R4	1	1 kΩ	0603	Not specified	Not specified	LED/current-limit resistor	N/A	N/A
R5, R6, R7	3	10 Ω	0603	Not specified	Not specified	Series resistor	N/A	N/A

Diodes / Protection

Table

Designator(s)	Qty	Value	Package	MPN	Manufacturer	Description	Est. Unit	Ext.
D1	1	Schottky diode, 40 V, 1 A	SOD-123	1N5819HW-7-F	Diodes Incorporated	Schottky diode	$0.03279	$0.03279
D2	1	USB TVS array	SOT-23-6L	82400102	Würth Elektronik	7.7 V typ clamp TVS diode array	$0.73282	$0.73282
D3	1	RS-485 TVS	SOT-23	SM712	MDD	RS-485 transient voltage suppressor	$0.02142	$0.02142

LEDs

Table

Designator(s)	Qty	Value	Package	MPN	Manufacturer	Description	Est. Unit	Ext.
PWR	1	Indicator LED	0805	Not specified	Not specified	Power indicator LED	N/A	N/A

Switches

Table

Designator(s)	Qty	Value	Package	MPN	Manufacturer	Description	Est. Unit	Ext.
RST, BOOT	2	SPST-NO tactile switch	Side-actuated SMD	TL3330AF260QG	E-Switch	Right-angle tactile switch	$0.31	$0.62

Connectors

Table

Designator(s)	Qty	Value	Package	MPN	Manufacturer	Description	Est. Unit	Ext.
USB1	1	USB-C receptacle	24-pin USB-C, 8.94 × 7.3 mm	TYPE-C-31-M-12	Korean Hroparts Elec	USB Type-C receptacle	$0.15864	$0.15864

Transistors

Table

Designator(s)	Qty	Value	Package	MPN	Manufacturer	Description	Est. Unit	Ext.
Q1, Q2	2	N-channel MOSFET	SOT-23-3	BSS138	onsemi	50 V, 220 mA N-channel MOSFET	$0.00745	$0.01490

Integrated Circuits / Regulators

Table

Designator(s)	Qty	Value	Package	MPN	Manufacturer	Description	Est. Unit	Ext.
IC1	1	USB-UART bridge	SOIC-16	CH340C	WCH / Wah	USB-to-serial converter	$0.50530	$0.50530
IC3	1	RS-485 transceiver	SOIC-8	MAX3485CSA+	Maxim Integrated	Half-duplex RS-485 / RS-422 transceiver	$3.00600	$3.00600
U1	1	3.3 V LDO regulator	SOT-223	AMS1117-3.3	AMS	3.3 V linear regulator	$0.02140	$0.02140

DNP / Excluded From BOM

Table

Designator	Reason
U2	User requested not populated
A RS485 B	User requested not populated
J1	User requested not populated
J2	User requested not populated

Cost Summary

Populated BOM quantity: 32 components
Known-priced subtotal: $5.11
Items without available pricing: capacitors, resistors, and PWR LED
Estimated total using available pricing only: $5.11+
Actual total will be higher once specific priced passives and LED are selected.

nathansfb64

Export this BOM as a CSV with the DNP parts excluded.

Thought for 4 sec

flux

I’ll create a CSV BOM file with the requested DNP parts excluded and include the grouped line items plus cost fields.

Worked for 37 sec

flux

Done — CSV BOM created with U2, A RS485 B, J1, and J2 excluded:

https://cdn2.flux.ai/flux-comment-files/files/commentFileId-13a991fa5f1887d9f6d51b42ac1ad0f00240ca202d54a4416248e1a81651252d.csv?GoogleAccessId=autopilot-sa-d60c62b%40graviton-mvp.iam.gserviceaccount.com&Expires=4937765499&Signature=n8BPNoKbQZD8svCdTurrpFUNu5IZ8UvrtHoY7fxf2ZFy8GuTl9Fk0%2BPHwpo%2Bd2WmTFp0YcFznMm4KRBcFFfHSKOPtQYI8UbGL%2BGf%2BdYqOCxLij2vMryix7Y7E5cMpgo1L4uYdiNc9VVuWYf5doG7vbv5CihdvXKM33wOPOoqtF4XOEP%2FynblI360S6hWRoFRXtjqsXdeZ2jUDEddoXyoir8JU768fmIttsZLijerDp6KQ4q%2BY8XiXK7dxhi2NBDd9sJwy1ohfWWBrpgLdBYINr7jo4XPAw9EA5GY%2FvPkVCfixS1rGOeyu1D4wLhbLVfbnsgqog%2FOn0md1BKgiUmHKQ%3D%3D

Known-priced subtotal in the CSV is $5.11327, excluding unpriced passives/LED.

Review BOM and design

Find passive MPNs

Run design review

Reduce BOM cost

Explain DNP handling

Files

Schematic

Layout

3D View

ESP_RX

GPIO36

Capacitance

10uF

ESP_RX

CC1

Capacitance

10uF

ESP_TX

RS485_B

USBDP

RS485_TX

RS485_EN

Resistance

10kΩ

C11

Capacitance

0.1uF

RS485_TX

USBDN

GPIO15

GPIO14

Capacitance

10uF

ESP_TX

GPIO21

USBDP

GPIO34

RS485_B

GPIO25

CC2

GPIO27

ESP_IO0

Resistance

10 Ω

Resistance

5.1kΩ

GPIO25

USBDN

ESP_IO0

GPIO22

Resistance

10 Ω

Capacitance

0.1uF

GPIO16

Resistance

1kΩ

RS485_A

GPIO5

Resistance

5.1kΩ

ESP_IO0

CC1

USBDP

GPIO13

GPIO17

GPIO12

RS485_EN

GPIO35

GPIO16

GPIO33

Resistance

10 Ω

GPIO12

RS485_RX

C10

Capacitance

0.1uF

USBDN

ESP_RX

GPIO33

Capacitance

0.1uF

Capacitance

0.1uF

GPIO36

GPIO32

GPIO15

USBDN

ESP_EN

USBDP

GPIO2

RS485_RX

C12

Capacitance

0.1uF

GPIO26

GPIO13

GPIO22

Resistance

10kΩ

CC2

GPIO2

GPIO39

GPIO26

RS485_A

GPIO39

USBDN

GPIO32

ESP_EN

GPIO14

GPIO21

ESP_TX

Resistance

10kΩ

ESP_EN

GPIO23

ESP_IO0

GPIO5

GPIO27

ESP_EN

GPIO17

USBDP

GPIO35

+3V3

VBUS

+3V3

+5V

+3V3

+5V

+3V3

VBUS

+5V

+3V3

PWR

Capacitance

10uF

Capacitance

10uF

RST

USB1

TERM

IC3

BOOT

IC1

A RS485 B

ESP32 RS485 (Modbus) Controller Reference Design